When The Milky Way Dies

We won’t know if it did 

Cosmic Collision 

Universe Cosmic Collisions

 

Milky Way Has 4 Billion Years to Live

Four billion years from now, our galaxy, the Milky Way, will collide with our large spiraled neighbor, Andromeda.

The galaxies as we know them will not survive.

In fact, our solar system is going to outlive our galaxy. At that point, the sun will not yet be a red giant star – but it will have grown bright enough to roast Earth’s surface. Any life
forms still there, though, will be treated to some pretty spectacular cosmic choreography.

Currently, Andromeda and the Milky Way are about 2.5 million light-years apart. Fueled by gravity, the two galaxies are hurtling toward one another at 402,000 kilometers per hour.
But even at that speed, they won’t meet for another four billion years. Then, the two galaxies will collide head-on and fly through one another, leaving gassy, starry tendrils in their
wakes. For eons, the pair will continue to come together and fly apart, scrambling stars and redrawing constellations until eventually, after a billion or so years have passed, the two
galaxies merge.

Then, the solar system will have a new cosmic address: A giant elliptical galaxy, formed by the collision and merger of the Milky Way and Andromeda.

Source Nadia Drake

 

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The Gravitational Collapse

Gravitational collapse is the inward fall of an astronomical object due to the influence of its own gravity which tends to draw the object toward its center of mass. In any stable body, this gravitational force is counterbalanced by the internal pressure of the body acting in the opposite direction. If the gravitational force is stronger than the forces acting outward, the equilibrium becomes unstable and a collapse occurs until the internal pressure increases sufficiently that equilibrium is once again attained (the exception being a black hole).

diagram - collapse - star

Because gravity is weak compared to other fundamental forces, gravitational collapse is usually associated with very massive bodies or collections of bodies, such as stars (including collapsed stars such as supernovaeneutron stars and black holes) and massive collections of stars such as globular clusters and galaxies.

Gravitational collapse is at the heart of structure formation in the universe. An initial smooth distribution of matter will eventually collapse and cause a hierarchy of structures, such as clusters of galaxies, stellar groups, stars and planets. For example, a star is born through the gradual gravitational collapse of a cloud of interstellar matter. The compression caused by the collapse raises the temperature until nuclear fuel ignites in the center of the star and the collapse comes to a halt. The thermal pressure gradient (acting outward) balances the gravity (acting inward) and the star is in dynamic equilibrium between the two forces.

Gravitational collapse of a star occurs at the end of its lifetime, also called the death of the star. When all stellar energy sources are exhausted, the star will undergo a gravitational collapse. In this sense a star is in a “temporary” equilibrium state between a gravitational collapse at stellar birth and a further gravitational collapse at stellar death. The end state is called a compact star or stellar remnants.

The types of compact stars are:

The collapse to a white dwarf takes place over tens of thousands of years, while the star blows off its outer envelope to form a planetary nebula. If it has a companion star, a white dwarf-sized object can accrete matter from the companion star until it reaches the Chandrasekhar limit, at which point gravitational collapse takes over again. While it might seem that the white dwarf might collapse to the next stage (neutron star), they instead undergo runaway carbon fusion, blowing completely apart in a Type Ia supernova. Neutron stars are formed by gravitational collapse of larger stars, the remnant of other types of supernova.

Even more gigantic stars, above the Tolman–Oppenheimer–Volkoff limit cannot find a new dynamical equilibrium with any known force opposing gravity. Hence, the collapse continues with nothing to stop it. Once it collapses to within its Schwarzschild radius, not even light can escape from the star, therefore it becomes a black hole. According to theories, at some point later, the collapsing object will reach the maximum possible energy density for a certain volume of space or the Planck density (as there is nothing that can stop it). This is when the known laws of gravity cease to be valid. There are competing theories as to what occurs at this point, but it can no longer really be considered gravitational collapse at that stage.

It might be thought that a sufficiently large neutron star could exist inside its Schwarzschild radius and appear like a black hole without having all the mass compressed to a singularity at the center; however, this is a misconception .Within the event horizon, matter would have to move outward faster than the speed of light in order to remain stable and avoid collapsing to the center. No physical force therefore can prevent the star from collapsing to a singularity (at least within the currently understood framework of general relativity; this doesn’t hold for the Einstein–Yang–Mills–Dirac system). A model for nonspherical collapse in general relativity with emission of matter and gravitational waves has been presented.

See also

 

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Life and the Cells start small

Eukaryote (Eucaryotic cells)

 

A eukaryote
is any
organism whose cells contain a nucleus and
other
organelles enclosed within

membranes. Eukaryotes belong to the taxon Eukarya or
Eukaryota. The defining membrane-bound structure
that sets eukaryotic cells apart from
prokaryotic
cells (
Bacteria and Archaea) is the
nucleus, which contains the

genetic material, enclosed by
the nuclear
envelope
. The presence of
a nucleus gives eukaryotes their name, which comes from the
Greek ευ (eu,
“well”) and
κάρυον

(karyon, “nut” or
“kernel”). Eukaryotic cells also contain other membrane-bound organelles such
as
mitochondria or the

Golgi apparatus. In

addition, plants and algae contain

chloroplasts.
Many
unicellular organisms are

eukaryotes, such as protozoa. All
multicellular organisms are eukaryotes, including
animals, plants and

fungi.

Cell division
in eukaryotes differs from that in prokaryotes.
There are two types of division processes. In
mitosis, one
cell divides to produce two genetically identical cells. In
meiosis, which
is required in
sexual
reproduction
, one diploid cell
(having two instances of each chromosome, one from each parent)
undergoes
recombination of each pair of parental chromosomes, and
then two stages of cell division, resulting in four
haploid cells (gametes). Each
gamete has just one complement of
chromosomes, each a unique mix of the corresponding pair of parental
chromosomes.

The domain Eukaryota appears to be monophyletic, and so makes up one of the
three domains of
life. The two other domains,
Bacteria and Archaea, are prokaryotes
and have none of the above features.
Eukaryotes
represent a tiny minority of all living things; even in a human body
there are
10 times more microbes than human cells. However, due to their much
larger
size, their collective worldwide biomass is estimated at about equal to
that of
prokaryotes. Eukaryotes first developed approximately 1.6–2.1 billion
years
ago.

 

 

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The Star of Canis Minor

The Very Bright Procyon 

Procyon  is the brightest star in the constellation Canis Minor.
To the naked eye, it appears to be a single star, the eighth brightest
in the night sky with a visual apparent magnitude of 0.34.It is
classified as a binary star system, consisting of a white main-sequence
star of spectral type F5 IV–V, named Procyon A, and a faint white dwarf
companion of spectral type DQZ, named Procyon B. The reason for its
brightness is not its intrinsic luminosity but its relative closeness
to the Sun; as determined by the European Space Agency Hipparcos
astrometry satellite, it lies at a distance of just 11.46 light-years
(3.51 parsecs),and is therefore one of our nearest stellar neighbours.
Its closest neighboring star is Luyten’s Star, about 1.12 ly (0.34 pc)
away, and the latter would appear as a visual magnitude 2.7 star in the
night sky of a hypothetical planet orbiting Procyon.

Procyon in Canis Minor

Canis Minor

Visibility

Procyon is the eighth brightest star in the night sky, culminating at midnight on January 14.It forms one of the three vertices of the Winter Triangle asterism, in combination with Sirius and Betelgeuse.

The prime
period for evening viewing of Procyon is in late winter. It has a color
index is 0.42, and its hue has been described as having a faint yellow
tinge to it.

System

Procyon is a binary star system with a bright primary component,
Procyon A, having an apparent magnitude of 0.34, and a faint companion,
Procyon B, at magnitude 10.7. The primary has a stellar classification
of F5IV–V, indicating that it is a late-stage F-type main-sequence
star. The effective surface temperature of the star is an estimated
6,530 K, giving it a white hue. It is 1.4 times the solar mass , twice the solar
radius, and has 6.9 times the Sun’s luminosity . Procyon A is bright
for its spectral class, suggesting that it is a subgiant that has nearly fused its core hydrogen into helium, after which it will expand as “burning” moves outside the core. As it
continues to expand, the star will eventually swell to about 80 to 150
times its current diameter and become a red or orange color. This will
probably happen within 10 to 100 million years.

 

Like Sirius B, Procyon’s companion is a white dwarf that was inferred
from astrometric data long before it was observed. Its existence had
been postulated by Friedrich Bessel as early as 1844, and, although its
orbital elements had been calculated by Arthur Auwers in 1862 as part
of his thesis, Procyon B was not visually confirmed until 1896 when
John Martin Schaeberle observed it at the predicted position using the
36-inch refractor at Lick Observatory. It is more difficult to observe
from Earth than Sirius B, due to a greater apparent magnitude
difference and smaller angular separation from its primary. The average
separation of the two components is 15.0 AUs, a little less than the
distance between Uranus and the Sun, though the eccentric orbit carries
them as close as 8.9 AUs and as far as 21.0 AU.

At 0.6 M?, Procyon B is considerably less massive than Sirius B;
however, the peculiarities of degenerate matter ensure that it is
larger than its more famous neighbor, with an estimated radius of 8,600
km, versus 5,800 km for Sirius B. With a surface temperature of 7,740
K, it is also much cooler than Sirius B; this is a testament to its
lesser mass and greater age. The mass of the progenitor star for
Procyon B was about 2.5 M? and it came to the end of its life some 1.7
± 0.1 Gyr ago, after a main-sequence lifetime of 400–600 Myr. For this
reason, the age of Procyon A is expected to be at least 2 Gyr.

Source

Get more information at EarthSky

 

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most massive galaxies

Elliptical Galaxies

The most massive galaxies in the sky are giant elliptical galaxies. Their stars are on orbits that are randomly oriented within the galaxy (i.e. they are not rotating like disk galaxies). They are composed of old stars and have little to no dust. All elliptical galaxies probed so far have supermassive black holes in their center, and the mass of these black holes is correlated with the mass of the elliptical galaxy. They are also correlated to a property called sigma which is the speed of the stars at the far edge of the elliptical galaxies. Elliptical galaxies do not have disks around them, although some bulges of disk galaxies look similar to elliptical galaxies. One is more likely to find elliptical galaxies in more crowded regions of the universe (such as galaxy clusters).

Astronomers now see elliptical galaxies as some of the most evolved systems in the universe. It is widely accepted that the main driving force for the evolution of elliptical galaxies is mergers of smaller galaxies. These mergers can be extremely violent; galaxies often collide at speeds of 500 kilometers per second.

Many galaxies in the universe are gravitationally bound to other galaxies, that is to say they will never escape the pull of the other galaxy. If the galaxies are of similar size, the resultant galaxy will appear similar to neither of the two galaxies merging, but would instead be an elliptical galaxy. An image of an ongoing merger of equal sized disk galaxies is shown left.

In the Local Group, the Milky Way and M31 (the Andromeda Galaxy) are gravitationally bound, and currently approaching each other at high speed. If the two galaxies do meet they will pass through each other, with gravity distorting both galaxies severely and ejecting some gas, dust and stars into intergalactic space. They will travel apart, slow down, and then again be drawn towards each other, and again collide.

Eventually both galaxies will have merged completely, streams of gas and dust will be flying through the space near the newly formed giant elliptical galaxy. M31 is actually already distorted: the edges are warped. This is probably because of interactions with its own galactic companions, as well as possible mergers with dwarf spheroidal galaxies in the recent past – the remnants of which are still visible in the disk populations.

In our epoch, large concentrations of galaxies (clusters and superclusters) are still assembling.

While scientists have learned a great deal about ours and other galaxies, the most fundamental questions about formation and evolution remain only tentatively answered.

Source

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This Is Hinode my Sun

Hinode…  formerly Solar-B, is a Japan Aerospace Exploration Agency Solar mission with United States and United Kingdom collaboration. It is the follow-up to the Yohkoh(Solar-A) mission and it was launched on the final flight of the M-V-7 rocket from Uchinoura Space Center, Japan on 22 September 2006 at 21:36 UTC (23 September, 06:36 JST).

Source

autumn-thumbn on hinode post

Hinode – the unsun- unthank chair

 

Initial orbit was perigee height 280 km, apogee height 686 km, inclination 98.3 degrees. Then the satellite maneuvered to the quasi-circular sun-synchronous orbit over the day/night terminator, which allows near-continuous observation of the Sun. On 28 October 2006, the probe’s instruments captured their first images.

The data from Hinode are being downloaded to the Norwegian, terrestrial Svalsat station, operated by Kongsberg a few kilometres west of Longyearbyen, Svalbard. From there, data are transmitted by Telenors through a fibre-optic network to mainland Norway at Harstad, and on to data users in North America, Europe and Japan.

 

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Scattered Objects – Kuiper Belt

The Scattered Disc

ColeyArtAstro-BG-Superbubble

A sparsely populated region, overlapping with the Kuiper belt but extending as far as 100 AU and farther. Scattered disc objects (SDOs) travel in highly elliptical orbits, usually also highly inclined to the ecliptic. Most models of Solar System formation show both KBOs and SDOs first forming in a primordial comet belt, whereas later gravitational interactions, particularly with Neptune, sent the objects spiraling outward, some into stable orbits (the KBOs) and some into unstable orbits, becoming the scattered disc. Due to its unstable nature, the scattered disc is believed to be the point of origin for many of the Solar System’s short-period comets. Their dynamic orbits occasionally force them into the inner Solar System, becoming first centaurs, and then short-period comets.

According to the Minor Planet Center, which officially catalogues all trans-Neptunian objects, a KBO, strictly speaking, is any object that orbits exclusively within the defined Kuiper belt region regardless of origin or composition. Objects found outside the belt are classed as scattered objects. However, in some scientific circles the term “Kuiper belt object” has become synonymous with any icy minor planet native to the outer Solar System believed to have been part of that initial class, even if its orbit during the bulk of Solar System history has been beyond the Kuiper belt (e.g. in the scattered-disc region). They often describe scattered disc objects as “scattered Kuiper belt objects”. Eris, which is known to be more massive than Pluto, is often referred to as a KBO, but is technically an SDO. A consensus among astronomers as to the precise definition of the Kuiper belt has yet to be reached, and this issue remains unresolved.

The centaurs, which are not normally considered part of the Kuiper belt, are also believed to be scattered objects, the only difference being that they were scattered inward, rather than outward. The Minor Planet Center groups the centaurs and the SDOs together as scattered objects.

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The Kuiper Belt

Outer Region of The Solar System

The Kuiper belt – sometimes called the Edgeworth–Kuiper belt, is a region of the Solar System beyond the planets, extending from the orbit of Neptune (at 30 AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but it is far larger—20 times as wide and 20 to 200 times as massive. Like the asteroid belt, it consists mainly of small bodies, or remnants from the Solar System’s formation. Although most asteroids are composed primarily of rock and metal, most Kuiper belt objects are composed largely of frozen volatiles (termed “ices”), such as methane, ammonia and water. The Kuiper belt is home to at least three dwarf planets: Pluto, Haumea, and Makemake. Some of the Solar System’s moons, such as Neptune’s Triton and Saturn‘s Phoebe, are also believed to have originated in the region.

ColeyArtAstro-BG-Superbubble

The Kuiper belt was named after Dutch-American astronomer Gerard Kuiper, though his role in hypothesising it has been heavily contested. Since it was discovered in 1992, the number of known Kuiper belt objects (KBOs) has increased to over a thousand, and more than 100,000 KBOs over 100 km (62 mi) in diameter are believed to exist. The Kuiper belt was initially thought to be the main repository for periodic comets, those with orbits lasting less than 200 years. However, studies since the mid-1990s have shown that the belt is dynamically stable, and that comets’ true place of origin is the scattered disc, a dynamically active zone created by the outward motion of Neptune 4.5 billion years ago; scattered disc objects such as Eris have extremely eccentric orbits that take them as far as 100 AU from the Sun.

The Kuiper belt should not be confused with the hypothesized Oort cloud, which is a thousand times more distant. The objects within the Kuiper belt, together with the members of the scattered disc and any potential Hills cloud or Oort cloud objects, are collectively referred to as trans-Neptunian objects (TNOs).

Pluto is the largest member of the Kuiper belt, and the second largest known TNO, the largest being Eris in the scattered disc. Originally considered a planet, Pluto’s status as part of the Kuiper belt caused it to be reclassified as a “dwarf planet” in 2006. It is compositionally similar to many other objects of the Kuiper belt, and its orbital period is characteristic of a class of KBOs, known as “plutinos“, that share the same 2:3 resonance with Neptune.

History

After the discovery of Pluto in 1930, many speculated that it might not be alone. The region now called the Kuiper belt was hypothesized in various forms for decades. It was only in 1992 that the first direct evidence for its existence was found. The number and variety of prior speculations on the nature of the Kuiper belt have led to continued uncertainty as to who deserves credit for first proposing it.

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Gerard Kuiper

About Mr Kuiper Himself

portrait of gerard kuiper

Gerard Kuiper

Gerard Peter Kuiper (December 7, 1905 – December 23, 1973) was a Netherlands-born American astronomer after whom the Kuiper belt was named.

Kuiper, the son of a tailor in the village of Harenkarspel in North Holland, had an early interest in astronomy. He had extraordinarily sharp eyesight, allowing him to see magnitude 7.5 stars with the naked eye, about four times fainter than visible to normal eyes. He went to study at Leiden University in 1924, where at the time a very large number of astronomers had congregated.

He befriended fellow students Bart Bok and Pieter Oosterhoff and was taught by Ejnar Hertzsprung, Antonie Pannekoek, Willem de Sitter, Jan Woltjer, Jan Oort and the physicist Paul Ehrenfest. He received his B.Sc. in Astronomy in 1927 and continued straight on with his graduate studies.

Kuiper finished his doctoral thesis on binary stars with Hertzsprung in 1933, after which he traveled to California to become a fellow under Robert Grant Aitken at the Lick Observatory. In 1935 he left to work at the Harvard College Observatory where he met Sarah Parker Fuller, whom he married on June 20, 1936. Although he had planned to move to Java to work at the Bosscha Observatory, he took a position at the Yerkes Observatory of the University of Chicago and became an American citizen in 1937. In 1949, Kuiper initiated the Yerkes–McDonald asteroid survey (1950–1952).

Discoveries

Kuiper discovered two natural satellites of planets in the Solar System, namely Uranus‘s satellite Miranda and Neptune‘s satellite Nereid. In addition, he discovered carbon dioxide in the atmosphere of Mars and the existence of a methane-laced atmosphere above Saturn‘s satellite Titan in 1944. Kuiper also pioneered airborne infrared observing using a Convair 990 aircraft in the 1960s.

Kuiper spent most of his career at the University of Chicago, but moved to Tucson, Arizona, in 1960 to found the Lunar and Planetary Laboratory at the University of Arizona. Kuiper was the laboratory’s director until his death in 1973 while on vacation with his wife in Mexico. One of the three buildings at Arizona that makes up the LPL is named in his honour.

In the 1960s, Kuiper helped identify landing sites on the Moon for the Apollo program.

Kuiper discovered several binary stars which received “Kuiper numbers” to identify them, such as KUI 79.

Honours

Besides the minor planet 1776 Kuiper, the crater Kuiper on the Moon, craters on Mars and Mercury, the now-decommissioned Kuiper Airborne Observatory was also named after him.

Astronomers refer to a region of small minor planets beyond Neptune as the “Kuiper belt“, since Kuiper had suggested that such small planets or comets may have formed there. However he believed that such objects would have been swept clear by planetary gravitational perturbations so that none or few would exist there today.

The Kuiper Prize, named in his honor, is the most distinguished award given by the American Astronomical Society‘s Division for Planetary Sciences, an international society of professional planetary scientists. The prize recognizes outstanding contributors to planetary science, and is awarded annually to scientists whose lifetime achievements have most advanced our understanding of planetary systems. Winners of this award include Carl Sagan, James Van Allen, and Eugene Shoemaker.

 

 

 

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This Is Intergalactic dust

USA.NM.VeryLargeArray.02

It Is Not A Sci-Fi Film!

Intergalactic dust is cosmic dust in between galaxies in intergalactic space. Evidence for intergalactic dust has been suggested as early as 1949, and study of it grew throughout the late 20th century. There are large variations in the distribution of intergalactic dust.

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Elgordo the Galaxy cluster

image A galaxy cluster located about 7 billion light years from Earth.

Elagordo – galaxy cluster located about 7 billion light years from Earth.

Massive Cluster

This is a clip from the Chandra website about elgordo.

•Scientists who discovered this galaxy cluster in 2012 nicknamed it “El Gordo” because of its gigantic mass.

•New data from Hubble indicate El Gordo may weigh 43 percent more than the original estimate.

•El Gordo is the most massive, the hottest, and gives off the most X-rays of any known cluster at its distance or beyond.

•Like the Bullet Cluster, El Gordo is the site of two galaxy clusters running into each other at several million miles per hour.El Gordo is located over 7 billion light years from Earth, meaning that it is being observed at a young age.

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The Solar System in the Milky Way

Comprehending the Huge Size of The Milky Way

It takes the Solar System about 240 million years to complete one orbit of the Galaxy (a Galactic year), so the Sun is thought to have completed 18–20 orbits during its lifetime and 1/1250 of a revolution since the origin of humans. Header Coley Art Astro - Cast The First Stone The orbital speed of the Solar System about the center of the Galaxy is approximately 220 km/s or 0.073% of the speed of light. At this speed, it takes around 1,400 years for the Solar System to travel a distance of 1 light-year, or 8 days to travel 1 AU (astronomical unit). 0000-milkywaybutton-cmc Galaxy rotation curve for the Milky Way. Vertical axis is speed of rotation about the Galactic Center. Horizontal axis is distance from the Galactic Center in kpcs. The Sun is marked with a yellow ball. The observed curve of speed of rotation is blue. The predicted curve based upon stellar mass and gas in the Milky Way is red. Scatter in observations roughly indicated by gray bars. The difference is due to dark matter.

Galactic rotation

The stars and gas in the Galaxy rotate about its center differentially, meaning that the rotation period varies with location. As is typical for spiral galaxies, the orbital speed of most stars in the Galaxy does not depend strongly on their distance from the center. Away from the central bulge or outer rim, the typical stellar orbital speed is between 210 and 240 km/s. Hence the orbital period of the typical star is directly proportional only to the length of the path traveled. Milkyway_Size This is unlike the situation within the Solar System, where two-body gravitational dynamics dominate and different orbits have significantly different velocities associated with them. The rotation curve (shown in the figure) describes this rotation. Toward the center of the galaxy the orbit speeds are too low while beyond 7 kpcs the speeds are too high to match what would be expected from the universal law of gravitation. If the Galaxy contained only the mass observed in stars, gas, and other baryonic (ordinary) matter, the rotation speed would decrease with distance from the center. However, the observed curve is relatively flat, indicating that there is additional mass that cannot be detected directly with electromagnetic radiation. This inconsistency is attributed to dark matter. Alternatively, a minority of astronomers propose that a modification of the law of gravity may explain the observed rotation curve. The Sun is near the inner rim of the Galaxy’s Orion Arm, within the Local Fluff of the Local Bubble, and in the Gould Belt, at a distance of 8.33 ± 0.35 kiloparsecs (27,200 ± 1,100 ly) from the Galactic Center. The Sun is currently 5–30 parsecs (16–98 ly) from the central plane of the Galactic disk. The distance between the local arm and the next arm out, the Perseus Arm, is about 2,000 parsecs (6,500 ly). The Sun, and thus the Solar System, is found in the Galactic habitable zone.

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William Hyde Wollaston

Wollaston Portrait

Wollaston Portrait

William Hyde Wollaston PRS (6 August 1766 – 22 December 1828) was an English chemist and physicist who is famous for discovering two chemical elements; he also developed a way to process platinum ore into malleable ingots.

Biography

Wollaston was born in East Dereham, Norfolk, the son of the priest-astronomer Francis Wollaston (1737–1815) and his wife Althea Hyde. The family, which included 17 children, was financially well-off and were part of an intellectually stimulating environment. Wollaston was educated at Gonville and Caius College, Cambridge: in 1793 he obtained a doctorate in medicine from Cambridge University, and was a fellow of his college from 1787 to 1828.

He worked as a physician in rural areas between 1793 and 1797, then moved to London. During his studies, Wollaston had become interested in chemistry, crystallography, metallurgy and physics. In 1800, after he had received a large sum of money from one of his older brothers, he left medicine. He concentrated on pursuing his interests in chemistry and other subjects outside his trained vocation.

He was elected a Fellow of the Royal Society in 1793, where he became an influential member. He served as president in 1820. In 1822 he was elected a Foreign Honorary Member of the American Academy of Arts and Sciences.

Wollaston never married. He died in London in 1828 and was buried in Chislehurst, England.

Work

After having established a partnership with Smithson Tennant in 1800 in order to produce and sell chemical products, Wollaston became wealthy by developing the first physico-chemical method for processing platinum ore in practical quantities. He held the details of the process secret until near his death and made huge profits for about 20 years by being the only supplier in England of the product which had many of the same qualities as gold, but were much cheaper.

Chemical analysis related to the process of purifying platinum, led Wollaston to discover the elements palladium (symbol Pd) in 1802 and rhodium (symbol Rh) in 1804.

Anders Gustav Ekeberg discovered tantalum in 1802, however, Wollaston declared it was identical with niobium (then known as columbium). Later Heinrich Rose proved in 1846 that columbium and tantalum were indeed different elements and he renamed columbium “niobium“.

The mineral wollastonite was later named after Wollaston for his contributions to crystallography and mineral analysis.

Wollaston also performed important work in electricity. In 1801, he performed an experiment showing that the electricity from friction was identical to that produced by voltaic piles. During the last years of his life he performed electrical experiments that would pave the way to the eventual design of the electric motor. Controversy erupted when Michael Faraday constructed the first working electric motor and hastily published his results without acknowledging Wollaston’s previous work. Wollaston, however, saw nothing wrong with Faraday’s action. Wollaston also invented a battery that allowed the zinc plates in the battery to be raised out of the acid, so that the zinc would not be dissolved as quickly as it would if it were in the battery all the time.

His optical work was important as well, where he is remembered for his observations of dark Fraunhofer lines in the solar spectrum (1802), which eventually led to the discovery of the elements in the Sun. He invented the camera lucida (1807), the reflecting goniometer (1809), and the Wollaston prism. He also developed the first lens specifically for camera lens called Wollaston’s meniscus lens, or just meniscus lens, in 1812. The lens was designed to improve the image projected by the camera obscura. By changing the shape of the lens, Wollaston was able to project a flatter image, eliminating much of the distortion that was a problem with many of that day’s biconvex lenses.

Wollaston also devised a cryophorus, “a glass container containing liquid water and water vapor. It is used in physics courses to demonstrate rapid freezing by evaporation.” He used his Bakerian lecture in 1805, On the Force of Percussion, to defend Gottfried Leibniz‘s principle of vis viva, an early formulation of the conservation of energy. Wollaston was too ill to deliver his final Bakerian in 1828 and dictated it to Henry Warburton who read it on 20 November.

Wollaston’s attempt to demonstrate the presence of glucose in the blood serum of diabetics was unsuccessful due to the limited means of detection available to him. His 1811 paper “On the non-existence of sugar in the blood of persons labouring under diabetes mellitus” concluded that sugar must travel via lymphatic channels from the stomach directly to the kidneys, without entering the bloodstream. Wollaston supported this theory by referring to the thesis of a young medical student at Edinburgh, Charles Darwin (1758–1778), “Experiments establishing a criterion between mucaginous and purulent matter. And an account of the retrograde motions of the absorbent vessels of animal bodies in some diseases.” This Charles Darwin was the eldest son of Erasmus Darwin and not his more famous nephew, Charles Robert Darwin.

Wollaston prophetically foretold that if once an accurate knowledge were gained of the relative weights of elementary atoms, philosophers would not rest satisfied with the determination of mere numbers, but would have to gain a geometrical conception of how the elementary particles were placed in space. Jacobus Henricus van ‘t Hoff‘s La Chimie dans l’Espace was the first practical realisation of this prophecy.

Wollaston was part of a royal commission that recommended adoption of the imperial gallon in 1814. He served on the government’s Board of Longitude between 1818 and 1828 and was part of royal commission that opposed adoption of the metric system (1819).

 

 

 

 

 

 

 

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We Landed On A Comet

rosetta orbit

Rosetta & Philae Make History

Quite a week for science and the E.S.A. – I have created this post as a summary to check back on. Not to reassure myself it actually happened but as a reference point!

Rosetta’s lander has completed its primary science mission after nearly 57 hours on Comet 67P/Churyumov–Gerasimenko.

After being out of communication visibility with the lander since 09:58 GMT / 10:58 CET on Friday, Rosetta regained contact with Philae at 22:19 GMT /23:19 CET last night. The signal was initially intermittent, but quickly stabilised and remained very good until 00:36 GMT / 01:36 CET this morning. 

In that time, the lander returned all of its housekeeping data, as well as science data from the targeted instruments, including ROLIS, COSAC, Ptolemy, SD2 and CONSERT. This completed the measurements planned for the final block of experiments on the surface.

Latest news on 17 November

The descent images

 

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Moons of Uranus

Uranus and 27 Moon’s

Planets size compared diagram

The Sun & Planets

Uranus, the seventh planet of the Solar System, has 27 known moons, all of which are named after characters from the works of William Shakespeare and Alexander Pope. William Herschel discovered the first two moons, Titania and Oberon, in 1787, and the other three ellipsoidal moons were discovered in 1851 by William Lassell (Ariel and Umbriel) and in 1948 by Gerard Kuiper (Miranda). These five have planetary mass, and so would be considered (dwarf) planets if they were in direct orbit about the Sun. The remaining moons were discovered after 1985, either during the Voyager 2 flyby mission or with the aid of advanced Earth-based telescopes.

 

Uranian moons are divided into three groups: thirteen inner moons, five major moons, and nine irregular moons. The inner moons are small dark bodies that share common properties and origins with the planet’s rings. The five major moons are massive enough to have achieved hydrostatic equilibrium, and four of them show signs of internally driven processes such as canyon formation and volcanism on their surfaces. The largest of these five, Titania, is 1,578 km in diameter and the eighth-largest moon in the Solar System, and about 20 times less massive than the Moon. Uranus’s irregular moons have elliptical and strongly inclined (mostly retrograde) orbits at great distances from the planet.

 

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Joseph von Fraunhofer

Fraunhofer

Fraunhofer

Joseph Fraunhofer, ennobled in 1824 as Ritter von Fraunhofer (6 March 1787 – 7 June 1826) was a German optician. He is known for the discovery of the dark absorption lines known as Fraunhofer lines in the Sun’s spectrum, and for making excellent optical glass and achromatic telescope objectives.

 

Fraunhofer lines

In physics and optics, the Fraunhofer lines are a set of spectral lines named after the German physicist Joseph von Fraunhofer (1787–1826) . The lines were originally observed as dark features (absorption lines) in the optical spectrum of the Sun.

Discovery

In 1802, the English chemist William Hyde Wollaston was the first person to note the appearance of a number of dark features in the solar spectrum. In 1814, Fraunhofer independently rediscovered the lines and began a systematic study and careful measurement of the wavelength of these features. In all, he mapped over 570 lines, and designated the principal features with the letters A through K, and weaker lines with other letters. Modern observations of sunlight can detect many thousands of lines.

About 45 years later Kirchhoff and Bunsen noticed that several Fraunhofer lines coincide with characteristic emission lines identified in the spectra of heated elements. It was correctly deduced that dark lines in the solar spectrum are caused by absorption by chemical elements in the Solar atmosphere. Some of the observed features were identified as telluric lines originating from absorption in oxygen molecules in the Earth’s atmosphere.

Source

The Fraunhofer lines are typical spectral absorption lines. These dark lines are produced whenever a cold gas is between a broad spectrum photon source and the detector. In this case, a decrease in the intensity of light in the frequency of the incident photon is seen as the photons are absorbed, then re-emitted in random directions, which are mostly in directions different from the original one. This results in an absorption line, since the narrow frequency band of light initially traveling toward the detector, has been turned into heat or re-emitted in other directions. By contrast, if the detector sees photons emitted directly from a glowing gas, then the detector often sees photons emitted in a narrow frequency range by quantum emission processes in atoms in the hot gas, resulting in an emission line. In the Sun, Fraunhofer lines are seen from gas in the outer regions of the Sun, which are too cold to directly produce emission lines of the elements they represent.

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Mimas Moon

The surface area of Mimas is slightly less than the land area of Spain. The low density of Mimas, 1.15 g/cm³, indicates that it is composed mostly of water ice with only a small amount of rock. Due to the tidal forces acting on it, Mimas is noticeably prolate; its longest axis is about 10% longer than the shortest. The ellipsoidal shape of Mimas is especially noticeable in some recent images from the Cassini probe.

Mimas & I, via Saturn.

Mimas & I, via Saturn.

 

Mimas’s most distinctive feature is a giant impact crater 130 kilometres (81 mi) across, named Herschel after the discoverer of Mimas. Herschel’s diameter is almost a third of Mimas’s own diameter; its walls are approximately 5 kilometres (3.1 mi) high, parts of its floor measure 10 kilometres (6.2 mi) deep, and its central peak rises 6 kilometres (3.7 mi) above the crater floor. If there were a crater of an equivalent scale on Earth it would be over 4,000 kilometres (2,500 mi) in diameter, wider than Australia. The impact that made this crater must have nearly shattered Mimas: fractures can be seen on the opposite side of Mimas that may have been created by shock waves from the impact travelling through Mimas’s body.

The Mimantean surface is saturated with smaller impact craters, but no others are anywhere near the size of Herschel. Although Mimas is heavily cratered, the cratering is not uniform. Most of the surface is covered with craters greater than 40 kilometres (25 mi) in diameter, but in the south polar region, craters greater than 20 kilometres (12 mi) are generally lacking.

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The Magnetospheric Van Allen

james van allen - black and white image standing with rockoon

J.Allen holding Rockoon.

James Alfred Van Allen (September 7, 1914 – August 9, 2006) was an American space scientist at the University of Iowa. He was instrumental in establishing the field of magnetospheric research in space.

The Van Allen radiation belts were named after him, following their discovery by his Geiger–Müller tube instruments on the 1958 satellites: (Explorer 1, Explorer 3, and Pioneer 3) during the International Geophysical Year. Van Allen led the scientific community for the inclusion of scientific research instruments on space satellites.

About Van Allen

Born in Mount Pleasant, Iowa on September 7, 1914, Van Allen was valedictorian of his high school class in 1931, and received his bachelor’s degree in physics, summa cum laude, from Iowa Wesleyan College in 1935. While an undergraduate at Iowa Wesleyan, he assisted the senior scientist of the second Byrd Expedition (1934–35) to Antarctica in preparing seismic and magnetic experimental equipment. (In 2004, the American Polar Society commemorated his work by presenting Van Allen with its Honors of the Society award.) He earned his master’s and doctorate from the University of Iowa in 1936 and 1939, respectively.

From 1940 through 1942, he helped develop radio proximity fuzes—detonators to increase the effectiveness of anti-aircraft fire—for the defense of ships. Sponsored by the National Defense Research Council, his work was conducted at the Carnegie Institution of Washington and at the Applied Physics Laboratory of Johns Hopkins University. In November 1942, he was commissioned as a naval officer, and he served 16 months on various ships in the South Pacific Fleet as assistant staff gunnery officer.

In 1946, Van Allen returned to the Applied Physics Laboratory where he organized and directed a team to conduct high-altitude experimental work using V2 and Aerobee rockets, and, in 1951, he accepted a Guggenheim research fellowship at the Brookhaven National Laboratory.

Later in 1951, Van Allen became professor and head of the University of Iowa Department of Physics and Astronomy, a position he held until he retired from teaching in 1985. During the 1950s, he and his graduate students used the UI football practice field to launch rockets and “rockoons”—rockets carried aloft by balloons—to conduct cosmic ray experiments above the atmosphere. A highlight of that work was the 1953 discovery of electrons believed to be the driving force behind the aurora. In 1956, he proposed the use of U.S. satellites for cosmic-ray investigations and through “preparedness and good fortune,” he later wrote, the experiment was selected as the principal payload for the first flight of a four-stage Juno I rocket in October 1957.

Van Allen played an important role in planning the 1957-58 International Geophysical Year (IGY) and carried out shipboard expeditions to Greenland and southward to the Ross Sea off the coast of Antarctica in 1957. IGY culminated in the Jan. 31, 1958 launch of Explorer 1 and its scientific payload. Van Allen’s instruments included a Geiger–Müller tube, which provided data and information that regions of intense radiation surround the Earth. The discovery marked the birth of the research field of magnetospheric physics, an enterprise that grew to involve more than 1,000 investigators in more than 20 countries.

In 1974 People Magazine listed Van Allen as one of the top 10 teaching college professors in the country. His former graduate students list among their accomplishments experiments on NASA’s Pioneer 10 and 11, Voyager 1 and 2, Galileo and Cassini spacecraft. Van Allen joined the American Geophysical Union (AGU) in 1948 and served as the organization’s president from 1982 until 1984. He has received the AGU’s highest honors, including the John A. Fleming Award in 1963 for eminence in geophysics and the William Bowie Medal in 1977 for outstanding contributions to fundamental geophysics and for unselfish cooperation in research.

Also, in 1962 Van Allen became the second recipient of the Daniel and Florence Guggenheim International Astronautical Award presented by the International Academy of Astronautics for noteworthy contributions to astronautics, and in March 2006 he received the 2006 Smithsonian National Air and Space Museum Trophy for lifetime achievement. In 1994, Van Allen received the 1994 Gerard P. Kuiper Prize from the Division of Planetary Sciences of the American Astronomical Society “in recognition of his many contributions to the field of planetary science, both through his investigations of planetary magnetospheres and through his advocacy of planetary exploration.” Also in 1994, he was presented with a lifetime

achievement award by NASA on the occasion of his 80th birthday and the American Geophysical Union’s 75th anniversary.

Aerobee and Rockoon

Discharged from the Navy in 1946, Van Allen returned to civilian research at APL. He organized and directed a team at Johns Hopkins University to conduct high-altitude experiments, using V-2 rockets captured from the Germans at the end of World War II. Van Allen decided a small sounding rocket was needed for upper atmosphere research and the Aerojet WAC Corporal and the Bumblebee missile were developed under a US Navy program. He drew specifications for the Aerobee and headed the committee that convinced the U.S. government to produce it. The first instrument-carrying Aerobee was the A-5, launched on March 5, 1948 from White Sands, carrying instruments for cosmic radiation research, reaching an altitude of 117.5 km.

Van Allen elected chairman of the V-2 Upper Atmosphere Panel on December 29, 1947. The panel was renamed Upper Atmosphere Rocket Research Panel on March 18, 1948; then Rocket and Satellite Research Panel on April 29, 1948. The panel suspended operations on May 19, 1960 and had a reunion on February 2, 1968.

Cmdr. Lee Lewis, Cmdr. G. Halvorson, S.F. Singer, and James A. Van Allen develop the idea for the Rockoon on March 1, 1949 during the Aerobee rocket firing cruise on the research vessel U.S.S. Norton Sound.

On April 5, 1950 Van Allen left Applied Physics Laboratories, to accept a John Simon Guggenheim Memorial Foundation research fellowship at the Brookhaven National Laboratory. The following year (1951) Van Allen accepted the position as head of the physics department at the University of Iowa. Before long, he was enlisting students in his efforts to discover the secrets of the wild blue yonder and inventing ways to carry instruments higher into the atmosphere than ever before. By 1952, Van Allen was the first to devise a balloon-rocket combination that lifted rockets on balloons high above most of the Earth’s atmosphere before firing them even higher. The rockets were ignited after the balloons reached an altitude of 16 kilometers.

As Time magazine reported in 1959, “Van Allen’s ‘Rockoons’ could not be fired in Iowa for fear that the spent rockets would strike an Iowan or his house.” So Van Allen convinced the U.S. Coast Guard to let him fire his rockoons from the icebreaker Eastwind that was bound for Greenland. “The first balloon rose properly to 70,000 ft., but the rocket hanging under it did not fire. The second Rockoon behaved in the same maddening way. On the theory that extreme cold at high altitude might have stopped the clockwork supposed to ignite the rockets, Van Allen heated cans of orange juice, snuggled them into the third Rockoon’s gondola, and wrapped the whole business in insulation. The rocket fired.”

In 1953 the Rockoons and their science payloads fired off Newfoundland detected the first hint of radiation belts surrounding Earth. The low-cost Rockoon technique was later used by the Office of Naval Research and The University of Iowa research groups in 1953-55 and 1957, from ships at sea between Boston and Thule, Greenland.

In 1954, in a private discussion about the Redstone project with Ernst Stuhlinger, Wernher von Braun expressed his belief that they should have a “real, honest-to-goodness scientist” involved in their little unofficial satellite project. “I’m sure you know a scientist somewhere who would fill the bill, possibly in the Nobel Prize class, willing to work with us and to put some instruments on our satellite.” Stuhlinger, himself a cosmic ray researcher during his college years, and having worked with Van Allen at White Sands with V-2 rockets, was ready with his reply: “Yes, of course, I will talk to Dr. Van Allen.”

Stuhlinger followed this by a visit with Van Allen at his home in Princeton, New Jersey, where Van Allen was on sabbatical leave from Iowa to work on stellarator design. Van Allen later recounted, “Stuhlinger’s 1954 message was simple and eloquent. By virtue of ballistic missile developments at Army Ballistic Missile Agency (ABMA), it was realistic to expect that within a year or two a small scientific satellite could be propelled into a durable orbit around the earth (Project Orbiter)…. I expressed a keen interest in performing a worldwide survey of the cosmic-ray intensity above the atmosphere.”

In 1955, the U.S. announced Project Vanguard as part of the US contribution to the International Geophysical Year, a project to launch an artificial satellite into an orbit around the Earth. It was to be run by the US Navy and to be based on developing sounding rockets, which had the advantage that they were primarily used for non-military scientific experiments.

The symposium on “The Scientific Uses of Earth Satellites” was held on January 26 and 27, 1956 at the University of Michigan under sponsorship of the Upper Atmosphere Rocket Research Panel, chaired by Dr. Van Allen. 33 scientific proposals were presented for inclusion in the IGY satellites. Van Allen’s presentation highlighted the use of planned U.S. satellites for continuing cosmic-ray investigations. At this same time his Iowa Group began preparations for scientific research instruments to be carried by ‘Rockoons‘ and Vanguard for the International Geophysical Year. Through “preparedness and good fortune,” as he later wrote, those scientific instruments were available for incorporation in the 1958 Explorer and Pioneer IGY launches.

Van Allen Probes

On Nov. 9, 2012 NASA renamed the Radiation Belt Storm Probes (RBSP), a mission to study Earth’s Van Allen radiation belts, as the Van Allen Probes mission in honor of the late James A. Van Allen, U.S. space pioneer and longtime distinguished professor of physics in the University of Iowa College of Liberal Arts and Sciences. The Applied Physics Laboratory, where Dr. Van Allen worked for a decade, is responsible for the overall implementation and instrument management for RBSP. The primary mission is scheduled to last 2 years, with expendables expected to last for 4 years.

tn-4earth-coleyatastro

Love Earth

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the Draco constellation

Draco is a constellation in the far northern sky.

Draco is a constellation in the far northern sky. Its name is Latin for dragon. Draco is circumpolar (that is, never setting) for many observers in the northern hemisphere. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations today. The north pole of the ecliptic is in Draco. Draco can be seen all year.

The constellation of draco

 

Thuban (a Draconis) was the northern pole star from 3942 BC, when it moved farther north than Theta Boötis, until 1793 BC. The Egyptian Pyramids were designed to have one side facing north, with an entrance passage designed so that Thuban would be visible at night. Due to the effects of precession, it will once again be the pole star around the year 21000 AD. It is a blue-white giant star of magnitude 3.7, 309 light-years from Earth. The traditional name of Alpha Draconis, Thuban, means “head of the serpent”.
There are two other stars above magnitude 3 in Draco. The brighter of the two—and the brightest star in Draco—is Gamma Draconis, traditionally called Etamin or Eltanin. It is an orange giant star of magnitude 2.2, 148 light-years from Earth. The aberration of starlight was discovered in 1728 when James Bradley observed Gamma Draconis. Beta Draconis, traditionally called Rastaban, is a yellow giant star of magnitude 2.8, 362 light-years from Earth. Its name shares a meaning with Thuban, “head of the serpent”.

Draco is home to several double stars and binary stars.  Draconis is a double star with a yellow-hued primary of magnitude 2.8 and a white-hued secondary of magnitude 8.2 located south of the primary. The two are separated by 4.8 arcseconds. Mu Draconis, traditionally called Alrakis, is a binary star with two white components. Magnitude 5.6 and 5.7, the two components orbit each other every 670 years. The Alrakis system is 88 light-years from Earth. Nu Draconis is a similar binary star with two white components, 100 light-years from Earth. Both components are of magnitude 4.9 and can be distinguished in a small amateur telescope or a pair of binoculars. Omicron Draconis is a double star divisible in small telescopes. The primary is an orange giant of magnitude 4.6, 322 light-years from Earth.

The secondary is of magnitude 7.8. Psi Draconis is a binary star divisible in binoculars and small amateur telescopes, 72 light-years from Earth. The primary is a yellow-white star

of magnitude 4.6 and the secondary is a yellow star of magnitude 5.8. 16 Draconis and 17 Draconis are part of a triple star 400 light-years from Earth, divisible in medium-sized

amateur telescopes. The primary, a blue-white star of magnitude 5.1, is itself a binary with components of magnitude 5.4 and 6.5. The secondary is of magnitude 5.5 and the

system is 400 light-years away. 20 Draconis is a binary star with a white-hued primary of magnitude 7.1 and a yellow-hued secondary of magnitude 7.3 located east-northeast of the

primary. The two are separated by 1.2 arc seconds at their maximum and have an orbital period of 420 years. As of 2012, the two components are approaching their maximum

separation. 39 Draconis is a triple star 188 light-years from Earth, divisible in small amateur telescopes. The primary is a blue star of magnitude 5.0, the secondary is a yellow star of magnitude 7.4, and the tertiary is a star of magnitude 8.0; the tertiary appears to be a close companion to the primary. 40 Draconis and 41 Draconis are a binary star divisible in small telescopes. The two orange dwarf stars are 170 light-years from Earth and are of magnitude 5.7 and 6.1.

R Draconis is a red Mira-type variable star with a period of about 8 months. Its average minimum magnitude is approximately 12.4, and its average maximum magnitude is approximately 7.6. It was discovered to be a variable star by Hans Geelmuyden in 1876.
The constellation contains the star recently named Kepler-10 which has been confirmed to be orbited by Kepler-10b, the smallest ever rocky Earth-sized planet detected outside of our solar system.

The Deep-sky Objects in Draco

One of the deep-sky objects in Draco is the Cat’s Eye Nebula (NGC 6543), a planetary nebula approximately 3,000 light-years away that was discovered by English astronomer William Herschel in 1786. It is 9th magnitude and was named for its appearance in the Hubble Space Telescope, though it appears as a fuzzy blue-green disk in an amateur telescope.NGC 6543 has a very complex shape due to gravitational interactions between the components of the multiple star at its center, the progenitor of the nebula approximately 1,000 years ago. It is located 9.6 arcminutes away from the north ecliptic pole to the west-northwest. It is also related to IC 4677, a nebula that appears as a bar 1.8 arcminutes to the west of the Cat’s Eye nebula. In long-term exposures, IC 4677 appears as a portion of a ring surrounding the planetary nebula.

There are several faint galaxies in Draco, one of which is the lenticular galaxy NGC 5866, sometimes considered to be Messier Object 102. Another is the Draco Dwarf Galaxy, one of the least luminous galaxies with an absolute magnitude of -8.6 and a diameter of only about 3,500 light years, discovered by Albert G. Wilson of Lowell Observatory in 1954.

Another dwarf galaxy found in this constellation is PGC 39058.
Draco also features several interacting galaxies and galaxy clusters. One such massive cluster is Abell 2218, located at a distance of 3 billion light-years (redshift 0.171). It acts as a gravitational lens for even more distant background galaxies, allowing astronomers to study those galaxies as well as Abell 2218 itself; more specifically, the lensing effect allows

astronomers to confirm the cluster’s mass as determined by x-ray emissions. One of the most well-known interacting galaxies is Arp 188, also called the “Tadpole Galaxy”.
Named for its appearance, which features a “tail” of stars 280,000 light-years long, the Tadpole Galaxy is at a distance of 420 million light-years (redshift 0.0314). The tail of stars drawn off the Tadpole Galaxy appears blue because the gravitational interaction disturbed clouds of gas and sparked star formation.

Q1634+706 is a quasar that holds the distinction of being the most distant object usually visible in an amateur telescope. At magnitude 14.4, it appears starlike, though it is at a distance of 12.9 billion light-years. The light of Q1634+706 has taken 8.6 billion years to reach Earth, a discrepancy attributable to the expansion of the universe.

Draco Mythology

Dragons in Greek mythology that may have inspired the constellation’s name include Ladon, the dragon who guarded the golden apples of the Hesperides. Hercules killed Ladon during his 12 labors; he was tasked with stealing the golden apples. The constellation of Hercules is depicted near Draco.
In Greco- Roman legend, Draco was a dragon killed by the goddess Minerva and tossed into the sky upon his defeat. The dragon was one of the Gigantes, who battled the Olympic gods for ten years. As Minerva threw the dragon, it became twisted on itself and froze at the cold North Celestial Pole before it could right itself. Sometimes, Draco is represented as the demon son of Gaia, Typhon.

 

Mythical Image of Draco

Mythical Draco

Traditional Arabic astronomy does not depict a dragon in modern-day Draco, which is called the Mother Camels. Instead, two hyenas, represented by Eta Draconis and Zeta Draconis are seen attacking a baby camel (a dim star near Beta Draconis), which is protected by four female camels, represented by Beta Draconis, Gamma Draconis, Nu Draconis, and Xi Draconis. The nomads who own the camels are camped nearby, represented by a cooking tripod composed of Upsilon, Tau, and Sigma Draconis.

 

In some mythology, Draco the dragon constellation had one- hundred magnificent heads, and gourded the golden apple tree, and put in the sky as a constellation for his bravery at protecting the apples. There are more myths than that, but that is one of the most common ones.

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Lacerta Constellation

Lacerta 2014-10-16 01.22.08

Lacerta in skymap

Not easy to see with the naked eye

Lacerta is one of the 88 modern constellations defined by the International Astronomical Union. Its name is Latin for lizard. A small, faint constellation, it was created in 1687 by the astronomer Johannes Hevelius. Its brightest stars form a “W” shape similar to that of Cassiopeia, and it is thus sometimes referred to as ‘Little Cassiopeia’. It is located between Cygnus, Cassiopeia and Andromeda on the northern celestial sphere. The northern part lies on the Milky Way.

Stars in Lacerta

Alpha Lacertae is a blue-white hued main-sequence star of magnitude 3.8, 102 light-years from Earth. It has a spectral type of A1 V and is an optical double star. Beta Lacertae is far dimmer, a yellow giant of magnitude 4.4, 170 light-years from Earth.

Roe 47 is a multiple star consisting of five components (magnitudes 5.8, 9.8, 10.1, 9.4, 9.8).

ADS 16402 is a binary star system in Lacerta, around which a planet orbits with some unusual properties. The Jupiter-sized planet exhibits an unexpectedly low density, about the same as cork. This planet is dubbed HAT P-1.

EV Lacertae is a rapidly spinning magnitude 10 red dwarf with a strong magnetic field. It is a flare star that can emit powerful flares potentially visible to the naked eye, thousands of times more energetic than any from Earth’s sun.

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Hot Jupiter’s – Basic Information

Need to know what is meant by the term hot jupiters?

Hot Jupiters (also called roaster planets, epistellar jovians, pegasids or pegasean planets) are a class of extrasolar planets whose characteristics are similar to Jupiter, but that have high surface temperatures because they orbit very close—between approximately 0.015 and 0.5 astronomical units (2.2×10^6 and 74.8×10^6 km)—to their parent stars, whereas Jupiter orbits its parent star (the Sun) at 5.2 astronomical units (780×10^6 km), causing low surface temperatures.

One of the best-known hot Jupiters is 51 Pegasi b, nicknamed Bellerophon. Discovered in 1995, it was the first extrasolar planet found orbiting a Sun-like star. 51 Pegasi b has an orbital period of about 4 days.

jups hot

 

Hot Jupiters have some common characteristics:

  • They have similar characteristics to Jupiter (gas giants, usually with masses close to or exceeding that of Jupiter, which is 1.9×1027 kg), however, orbit much more closely to the star and experience a high surface temperature.
  • They have a much greater chance of transiting their star as seen from a farther outlying point than planets of the same mass in larger orbits. The most notable of these are HD 209458 b, the first transiting hot Jupiter found, HD 189733 b, which was first mapped in 2007 by the Spitzer Space Telescope, and HAT-P-7b, which was recently observed by the Kepler mission.
  • Due to high levels of insolation they are of a lower density than they would otherwise be. This has implications for radius determination, because due to limb darkening of the planet’s background star during a transit, the planet’s ingress and egress boundaries are harder to determine.
  • They are all thought to have migrated to their present positions because there would not have been enough material so close to the star for a planet of that mass to have formed in situ.
  • Most of these have nearly circular orbits (low eccentricities). This is because their orbits have been circularized, or are being circularized, by the process of libration.
  • They exhibit high-speed winds distributing the heat from the day side to the night side, thus the temperature difference between the two sides is relatively low.
  • They are more common around F- and G-type stars and somewhat less common around K-type stars. Hot Jupiters around red dwarfs are very rare.

Hot Jupiters are the easiest extrasolar planets to detect via the radial-velocity method, because the oscillations they induce in their parent stars’ motion are relatively large and rapid, compared to other known types of planets.

They are thought to form at a distance from the star beyond the frost line, where the planet can form from rock, ice and gases. The planets then migrate inwards to the star where they eventually form a stable orbit. The planets usually move by type 2 migrations, or possibly via interaction with other planets. The migration happens during the solar nebula phase, and will typically stop when the star enters its T-Tauri phase. The strong stellar winds at this time remove most of the remaining nebula.

After their atmospheres and outer layers are stripped away (hydrodynamic escape), their cores may become chthonian planets. The amount of the outermost layers that is lost depends on the size and the material of the planet and the distance from the star. In a typical system a gas giant orbiting 0.02 AU around its parent star loses 5–7% of its mass during its lifetime, but orbiting closer than 0.015 AU can mean evaporation of the whole planet except for its core.

Terrestrial planets in systems with hot Jupiters

Simulations have shown that the migration of a Jupiter-sized planet through the inner protoplanetary disk (the region between 5 and 0.1 AU from the star) is not as destructive as one might assume. More than 60% of the solid disk materials in that region are scattered outward, including planetesimals and protoplanets, allowing the planet-forming disk to reform in the gas giant’s wake. In the simulation, planets up to two Earth masses were able to form in the habitable zone after the hot Jupiter passed through and its orbit stabilized at 0.1 AU. Due to the mixing of inner-planetary-system material with outer-planetary-system material from beyond the frost line, simulations indicated that the terrestrial planets that formed after a hot Jupiter’s passage would be particularly water-rich.

Retrograde orbit

It has been found that several hot Jupiters have retrograde orbits and this calls into question the theories about the formation of planetary systems, although rather than a planet’s orbit having been disturbed, it may be that the star itself flipped over early in their system’s formation due to interactions between the star’s magnetic field and the planet-forming disc. By combining new observations with the old data it was found that more than half of all the hot Jupiters studied have orbits that are misaligned with the rotation axis of their parent stars, and six exoplanets in this study have retrograde motion.

 

Ultra-short-period Jupiters are a class of hot Jupiters with orbital periods below 1 day and occur only around stars of less than about 1.25 solar masses.

Five ultra-short-period planets have been identified in the region of the Milky Way known as the galactic bulge. They were observed by the Hubble Space Telescope and first described by researchers from the Space Telescope Science Institute, the Universidad Catolica de Chile, Uppsala University, the High Altitude Observatory, the INAF–Osservatorio Astronomico di Padova and the University of California at Los Angeles.

More transiting hot Jupiters have been discovered, such as WASP-18b and WASP-19b, that have orbital periods of less than one day that do not support the hypothesis of the research above.

 

 

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The Niels Bohr Model

In 1911, Bohr travelled to England. At the time, it was where most of the theoretical work on the structure of atoms and molecules was being done. He met J. J. Thomson of the Cavendish Laboratory and Trinity College, Cambridge. He attended lectures on electromagnetism given by James Jeans and Joseph Larmor, and did some research on cathode rays, but failed to impress Thomson. He had more success with younger physicists like the Australian William Lawrence Bragg, and New Zealand’s Ernest Rutherford, whose 1911 Rutherford model of the atom had challenged Thomson’s 1904 plum pudding model.

Bohr received an invitation from Rutherford to conduct post-doctoral work
at Victoria University of Manchester, where Bohr met George de Hevesy and Charles Galton Darwin (whom Bohr referred to as “the grandson of the real Darwin”).
Bohr returned to Denmark in July 1912 for his wedding, and travelled around England and Scotland on his honeymoon. On his return, he became a privatdocent at the University of Copenhagen, giving lectures on thermodynamics. Martin Knudsen put Bohr’s name forward for a docent, which was approved in July 1913, and Bohr then began teaching medical students. His three papers, which later became famous as “the trilogy”, were published in Philosophical Magazine in July, September and November of that year. He adapted Rutherford’s nuclear structure to Max Planck’s quantum theory and so created his Bohr model of the atom.

Planetary models of atoms were not new, but Bohr’s treatment was. Taking the 1912 paper by Darwin on the role of electrons in the interaction of alpha particles with a nucleus as his starting point, he advanced the theory of electrons travelling in orbits around the atom’s nucleus, with the chemical properties of each element being largely determined by the number of electrons in the outer orbits of its atoms. He introduced the idea that an electron could drop from a higher-energy orbit to a lower one, in the process emitting a quantum of discrete energy. This became a basis for what is now known as the old quantum theory.

In atomic physics, the Rutherford–Bohr model or Bohr model, introduced by Niels Bohr in 1913, depicts the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus—similar in structure to the solar system, but with attraction provided by electrostatic forces rather than gravity. After the cubic model (1902), the plum-pudding model (1904), the Saturnian model (1904), and the Rutherford model (1911) came the Rutherford–Bohr model or just Bohr model for short (1913). The improvement to the Rutherford model is mostly a quantum physical interpretation of it. The Bohr model has been superseded, but the quantum theory remains sound.

 

The model’s key success lay in explaining the Rydberg formula for the spectral emission lines of atomic hydrogen. While the Rydberg formula had been known experimentally, it did not gain a theoretical underpinning until the Bohr model was introduced. Not only did the Bohr model explain the reason for the structure of the Rydberg formula, it also provided a justification for its empirical results in terms of fundamental physical constants.

The Bohr model is a relatively primitive model of the hydrogen atom, compared to the valence shell atom. As a theory, it can be derived as a first-order approximation of the hydrogen atom using the broader and much more accurate quantum mechanics and thus may be considered to be an obsolete scientific theory. However, because of its simplicity, and its correct results for selected systems (see below for application), the Bohr model is still commonly taught to introduce students to quantum mechanics or energy level diagrams before moving on to the more accurate, but more complex, valence shell atom. A related model was originally proposed by Arthur Erich Haas in 1910, but was rejected. The quantum theory of the period between Planck’s discovery of the quantum (1900) and the advent of a full-blown quantum mechanics (1925) is often referred to as the old quantum theory.

 

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Danish physicist Bohr

The Story of Niels Henrik David Bohr

Niels Bohr (7 October 1885 – 18 November 1962) was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922. Bohr was also a philosopher and a promoter of scientific research.
Bohr developed the Bohr model of the atom, in which he proposed that energy levels of electrons are discrete and that the electrons revolve in stable orbits around the atomic nucleus but can jump from one energy level (or orbit) to another. Although the Bohr model has been supplanted by other models, its underlying principles remain valid. He conceived the principle of complementarity: that items could be separately analysed in terms of contradictory properties, like behaving as a wave or a stream of particles. The notion of complementarity dominated Bohr’s thinking in both science and philosophy.

Bohr founded the Institute of Theoretical Physics at the University of Copenhagen, now known as the Niels Bohr Institute, which opened in 1920. Bohr mentored and collaborated with physicists including Hans Kramers, Oskar Klein, George de Hevesy and Werner Heisenberg. He predicted the existence of a new zirconium-like element, which was named hafnium, after the Latin name for Copenhagen, where it was discovered. Later, the element bohrium was named after him.
During the 1930s, Bohr helped refugees from Nazism. After Denmark was occupied by the Germans, he had a famous meeting with Heisenberg, who had become the head of the German nuclear energy project. In September 1943, word reached Bohr that he was about to be arrested by the Germans, and he fled to Sweden. From there, he was flown to Britain, where he joined the British Tube Alloys nuclear weapons project, and was part of the British mission to the Manhattan Project. After the war, Bohr called for international cooperation on nuclear energy. He was involved with the establishment of CERN and the Research Establishment Risø of the Danish Atomic Energy Commission, and became the first chairman of the Nordic Institute for Theoretical Physics in 1957.

Early years

Niels Bohr was born in Copenhagen, Denmark, on 7 October 1885, the second of three children of Christian Bohr, a professor of physiology at the University of Copenhagen, and Ellen Adler Bohr, who came from a wealthy Danish Jewish family prominent in banking and parliamentary circles. He had an elder sister, Jenny, and a younger brother Harald. Jenny became a teacher, while Harald became a mathematician and Olympic footballer who played for the Danish national team at the 1908 Summer Olympics in London. Niels was a passionate footballer as well, and the two brothers played several matches for the Copenhagen-based Akademisk Boldklub, with Niels as goalkeeper.
Bohr was educated at Gammelholm Latin School, starting when he was seven. In 1903, Bohr enrolled as an undergraduate at Copenhagen University. His major was physics, which he studied under Professor Christian Christiansen, the university’s only professor of physics at that time. He also studied astronomy and mathematics under Professor Thorvald Thiele, and philosophy under Professor Harald Høffding, a friend of his father.

In 1905, a gold medal competition was sponsored by the Royal Danish Academy of Sciences and Letters to investigate a method for measuring the surface tension of liquids that had been proposed by Lord Rayleigh in 1879. This involved measuring the frequency of oscillation of the radius of a water jet. Bohr conducted a series of experiments using his father’s laboratory in the university; the university itself had no physics laboratory. To complete his experiments, he had to make his own glassware, creating test tubes with the required elliptical cross-sections. He went beyond the original task, incorporating improvements into both Rayleigh’s theory and his method, by taking into account the viscosity of the water, and by working with finite amplitudes instead of just infinitesimal ones. His essay, which he submitted at the last minute, won the prize. He later submitted an improved version of the paper to the Royal Society in London for publication in the Philosophical Transactions of the Royal Society.

Harald became the first of the two Bohr brothers to earn a master’s degree, which he earned for mathematics in April 1909. Niels took another nine months to earn his. Students had to submit a thesis on a subject assigned by their supervisor. Bohr’s supervisor was Christiansen, and the topic he chose was the electron theory of metals. Bohr subsequently elaborated his master’s thesis into his much larger Doctor of Philosophy (dr. phil.) thesis. He surveyed the literature on the subject, settling on a model postulated by Paul Drude and elaborated by Hendrik Lorentz, in which the electrons in a metal are considered to behave like a gas. Bohr extended Lorentz’s model but was still unable to account for phenomena like the Hall effect, and concluded that electron theory could not fully explain the magnetic properties of metals. The thesis was accepted in April 1911, and Bohr conducted his formal defence on 13 May. Harald had received his doctorate the previous year. Bohr’s thesis was ground breaking, but attracted little interest outside Scandinavia because it was written in Danish, a Copenhagen University requirement at the time. In 1921, the Dutch physicist Hendrika Johanna van Leeuwen would independently derive a theorem from Bohr’s thesis that is today known as the Bohr–van Leeuwen theorem.

 

 

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Atomic orbital

Orbital Atom

An atomic orbital is a mathematical function that describes the wave-like behavior of either one electron or a pair of electrons in an atom. This function can be used to calculate the probability of finding any electron of an atom in any specific region around the atom’s nucleus. The term may also refer to the physical region or space where the electron can be calculated to be present, as defined by the particular mathematical form of the orbital.

Orbital black and white

Each orbital in an atom is characterized by a unique set of values of the three quantum numbers n, , and m, which correspond to the electron’s energy, angular momentum, and an angular momentum vector component, respectively. Any orbital can be occupied by a maximum of two electrons, each with its own spin quantum number. The simple names s orbital, p orbital, d orbital and f orbital refer to orbitals with angular momentum quantum number = 0, 1, 2 and 3 respectively. These names, together with the value of n, are used to describe the electron configurations. They are derived from the description by early spectroscopists of certain series of alkali metal spectroscopic lines as sharp, principal, diffuse, and fundamental. Orbitals for > 3 are named in alphabetical order (omitting j).

Atomic orbitals are the basic building blocks of the atomic orbital model (alternatively known as the electron cloud or wave mechanics model), a modern framework for visualizing the submicroscopic behavior of electrons in matter. In this model the electron cloud of a multi-electron atom may be seen as being built up (in approximation) in an electron configuration that is a product of simpler hydrogen-like atomic orbitals. The repeating periodicity of the blocks of 2, 6, 10, and 14 elements within sections of the periodic table arises naturally from the total number of electrons that occupy a complete set of s, p, d and f atomic orbitals, respectively.

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Emanuel Swedenborg

Emanuel Swedenborg born Emanuel Swedberg on 29 January 1688; died 29 March 1772) was a Swedish scientist, philosopher, theologian, revelator, and mystic. He is best known for his book on the afterlife, Heaven and Hell (1758).

Swedenborg had a prolific career as an inventor and scientist. In 1741, at age 53, he entered into a spiritual phase in which he began to experience dreams and visions, beginning on Easter weekend of April 6, 1744. This culminated in a ‘spiritual awakening’, in which he received revelation that he was appointed by the Lord to write The Heavenly Doctrine to reform Christianity. According to The Heavenly Doctrine the Lord had opened Swedenborg’s spiritual eyes, so that from then on he could freely visit heaven and hell and talk with angels, demons and other spirits; and the Last Judgment had already occurred, in 1757. However, he tells us that at this day it is very dangerous to talk with spirits, unless a person is in true faith, and is led by the Lord.

For the remaining 28 years of his life, Swedenborg wrote 18 published theological works, and several more which were unpublished. He termed himself a “Servant of the Lord Jesus Christ” in True Christian Religion, a work he published himself. Some followers of The Heavenly Doctrine believe that, of his theological works, only those which Swedenborg published himself are fully divinely inspired.

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Swedenborg

 

Scientific period

In 1715 Swedenborg returned to Sweden, where he devoted himself to natural science and engineering projects for the next two decades. A first step was his meeting with King Charles XII of Sweden in the city of Lund, in 1716. The Swedish inventor Christopher Polhem, who became a close friend of Swedenborg, was also present. Swedenborg’s purpose was to persuade the king to fund an observatory in northern Sweden.

However, the warlike king did not consider this project important enough, but did appoint Swedenborg assessor-extraordinary on the Swedish Board of Mines (Bergskollegium) in Stockholm.

From 1716 to 1718, Swedenborg published a scientific periodical entitled Daedalus Hyperboreus (“The Northern Daedalus), a record of mechanical and mathematical inventions and discoveries. One notable description was that of a flying machine, the same he had been sketching a few years earlier (see Flying Machine (Swedenborg)).

In 1718 Swedenborg published an article that attempted to explain spiritual and mental events in terms of minute vibrations or “tremulations”.

Upon the death of Charles XII, Queen Ulrika Eleonora ennobled Swedenborg and his siblings. It was common in Sweden during the 17th and 18th centuries for the children of bishops to receive this honour as a recognition of the services of their father. The family name was changed from Swedberg to Swedenborg.

In 1724, he was offered the chair of mathematics at Uppsala University, but he declined and said that he had mainly dealt with geometry, chemistry and metallurgy during his career. He also said that he did not have the gift of eloquent speech because of a stutter, as recognized by many acquaintances of his; it forced him to speak slowly and carefully, and there are no known occurrences of his speaking in public. The Swedish critic Olof Lagerkrantz proposed that Swedenborg compensated for his impediment by extensive argumentation in writing.

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Orion Magnificent Sky View

September Orion Sight

I have just seen Orion for the first time with my naked eye, in 2014. A beautiful site creeping up behind a tree from my window view. The only bad part of that is – it means winter is on it’s way already!

The Orion constellation is in my opinion, by far the most glorious of all to see.

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The Eridanus Constellation

Eridanus is a large constellation represented as a river.

It’s name is the Ancient Greek name for the Po River. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations. It is the sixth largest of the modern constellations.

The Stars of Eridanis

At its southern end is the magnitude 0.5 star Achernar, designated Alpha Eridani. 144 light-years from Earth, it is a blue-white hued main sequence star whose traditional name means “the river’s end”. Achernar is a very peculiar star because it is one of the flattest stars known. Observations indicate that its radius is about 50% larger at the equator than at the poles. This distortion occurs because the star is spinning extremely rapidly.

There are several other noteworthy stars in Eridanus, including some double stars. Beta Eridani, traditionally called Cursa, is a blue-white star of magnitude 2.8, 89 light-years from Earth. Its place to the south of Orion’s foot gives it its name, which means “the footstool”. Theta Eridani, called Acamar, is a binary star with blue-white components, distinguishable in small amateur telescopes and 161 light-years from Earth.

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Me Eridanis

The primary is of magnitude 3.2 and the secondary is of magnitude 4.3. 32 Eridani is a binary star 290 light-years from Earth. The primary is a yellow-hued star of magnitude 4.8 and the secondary is a blue-green star of magnitude 6.1. 32 Eridani is divisible in small amateur telescopes. 39 Eridani is a binary star divisible in small amateur telescopes, 206 light-years from Earth. The primary is an orange-hued giant star of magnitude 4.9 and the secondary is of magnitude 8. 40 Eridani is a triple star system consisting of an orange main-sequence star, a white dwarf, and a red dwarf.

The orange main-sequence star is the primary of magnitude 4.4, and the white secondary of magnitude 9.5 is the most easily visible white dwarf. The red dwarf, of magnitude 11, orbits the white dwarf every 250 years. The 40 Eridani system is 16 light-years from Earth. p Eridani is a binary star with two orange components, 27 light-years from Earth. The magnitude 5.8 primary and 5.9 secondary have an orbital period of 500 years.
Epsilon Eridani is a star with one extrasolar planet similar to Jupiter. It is an orange-hued main-sequence star of magnitude 3.7, 10.5 light-years from Earth. Its one planet, with an approximate mass of one Jupiter mass, has a period of 7 years.

Deep-sky objects

NGC 1535 is a small blue-gray planetary nebula visible in small amateur telescopes, with a disk visible in large amateur instruments. 2000 light-years away, it is of the 9th magnitude.
Eridanus contains the galaxies NGC 1232, NGC 1234 and NGC 1300, a grand design barred spiral galaxy.
NGC 1300 is a face-on barred spiral galaxy located 61 (plus or minus 8) million light-years away. The center of the bar shows an unusual structure: within the overall spiral structure, a grand design spiral that is 3,300 light-years in diameter exists. Its spiral arms are tightly wound.

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Meteor showers

The Nu Eridanids, a recently discovered meteor shower, radiate from the constellation between August 30 and September 12 every year; the shower’s parent body is an unidentified Oort cloud object. Another meteor shower in Eridanus is the Omicron Eridanids, which peak between November 1 and 10.

 

 

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Jan Hendrik Oort

Astronomy Pioneer Jan Oort

portrait of jan oort

Jan Oort

Jan Oort (28 April 1900 – 5 November 1992) was a Dutch astronomer who made significant contributions to the understanding of the Milky Way and a pioneer in the field of radio astronomy. His New York Times obituary called him “one of the century’s foremost explorers of the universe;” the European Space Agency website describes him as, “one of the greatest astronomers of the 20th century,” and states that he “revolutionised astronomy through his ground-breaking discoveries.” In 1955, Oort’s name appeared in Life Magazine’s list of the 100 most famous living people. He has been described as “putting the Netherlands in the forefront of postwar astronomy.”

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Microscopium – Constellation

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It’s a Southern Sky Costellation – that can be seen  in the Northern Sky

It can be seen with the naked eye in the southern sky, low on the horizon – in the early hours of the morning in August.

Microscopium  is a small constellation in the southern sky, defined in the 18th century by Nicolas Louis de Lacaille. Its brightest star is Gamma Microscopii of apparent magnitude 4.68, actually a yellow giant located around 381 light-years distant. Two star systems—WASP-7 and HD 205739—have been found to have planets, while another—AU Microscopii—has a debris disk.

History

The stars that now comprise Microscopium may formerly have belonged to the hind feet of Sagittarius. However, this is uncertain as, while its stars seem to be referred to by Al-Sufi as having been seen by Ptolemy, Al-Sufi does not specify their exact positions.
Its name is Latin for microscope; it was invented by Lacaille to commemorate the compound microscope. Its stars are very faint and hardly visible from most of the non-tropical northern hemisphere.

Characteristics

The brightest star is Gamma Microscopii, which has an apparent (visual) magnitude of 4.68. It is a yellow giant of spectral type G6III. Lying 381 light years away, It depicts the eyepiece of the microscope. Alpha Microscopii is also a yellow giant, though in this case a variable star, which ranges between apparent magnitudes 4.88 and 4.94. It is of spectral type G7III. Alpha has a 10th magnitude companion, visible in small telescopes. Epsilon Microscopii lies 165 light years away, and is a blue-white main sequence star of apparent magnitude 4.7, and spectral type A1V. Theta1 and Theta2 Microscopii make up a wide double whose components are splittable to the naked eye. Both are white A-class magnetic spectrum variable stars with strong metallic lines, similar to Cor Caroli. They mark the constellation’s specimen slide.
Many notable objects are too faint to be seen with the naked eye. AX Microscopii, better known as Lacaille 8760, is a red dwarf which lies only 12.9 light years from our solar system. HD 205739 has a jupiter-sized planet. WASP-7 is a star of magnitude 9.54 which has been discovered to have an exoplanet WASP-7b, while AU Microscopii is a young star which appears to be a solar system in the making with a debris disk. BO Microscopii is a rapidly rotating star, and PSR J2144-3933 is an unusual pulsar with an unusually long rotation period.

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Cecilia Helena Payne

Cecilia Helena Payne-Gaposchkin (May 10, 1900 – December 7, 1979) was a British-American astronomer and astrophysicist who, in 1925, proposed in her Ph.D. thesis an explanation for the composition of stars in terms of the relative abundances of hydrogen and helium.

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Cecilia at work.

 

 

Doctorate

Shapley persuaded Payne to write a doctoral dissertation, and so in 1925 she became the first person to earn a Ph.D. in astronomy from Radcliffe College (now part of Harvard). Her thesis was “Stellar Atmospheres, A Contribution to the Observational Study of High Temperature in the Reversing Layers of Stars”. Astronomer Otto Struve called it “undoubtedly the most brilliant Ph.D. thesis ever written in astronomy”.

Payne was able to accurately relate the spectral classes of stars to their actual temperatures by applying the ionization theory developed by Indian physicist Meghnad Saha. She showed that the great variation in stellar absorption lines was due to differing amounts of ionization at different temperatures, not to different amounts of elements. She correctly suggested that silicon, carbon, and other common metals seen in the Sun’s spectrum were found in about the same relative amounts as on Earth, but that helium and particularly hydrogen were vastly more abundant (for hydrogen, by a factor of about one million). Her thesis established that hydrogen was the overwhelming constituent of the stars (see Metallicity), and thus the most abundant element in the Universe.

When Payne’s dissertation was reviewed, astronomer Henry Norris Russell dissuaded her from concluding that the composition of the Sun is different from that of the Earth, contradicting the accepted wisdom at the time. However, he changed his mind four years later after deriving the same result by different means. After Payne was proven correct, Russell was often given the credit, although he himself acknowledged her work in his paper.

Early life

Cecilia Helena Payne was one of three children born in Wendover, England to Emma Leonora Helena (née Pertz) and Edward John Payne, a London barrister, historian and accomplished musician. Her mother came from a Prussian family and had two distinguished uncles, historian Georg Heinrich Pertz and the Swedenborgian writer James John Garth Wilkinson. Cecilia Payne’s father died when she was four years old, forcing her mother to raise the family on her own.

She attended St Paul’s Girls’ School. Her mother did not choose to spend money on her college education, but only on her brother’s. In 1919, she won a scholarship to Newnham College, Cambridge University, where she read botany, physics, and chemistry. Here, she attended a lecture by Arthur Eddington on his 1919 expedition to the island of Principe in the Gulf of Guinea off the west coast of Africa to observe and photograph the stars near a solar eclipse as a test of Einstein‘s general theory of relativity. This sparked her interest in astronomy. She completed her studies, but was not awarded a degree because of her sex; Cambridge did not grant degrees to women until 1948.

Cecilia Payne realized that her only career option in the U.K. was to become a teacher, so she looked for grants that would enable her to move to the United States. After meeting Harlow Shapley, the Director of the Harvard College Observatory, who had just begun a graduate program in astronomy, she left England in 1923. This was made possible by a fellowship to encourage women to study at the Observatory. The first student on the fellowship was Adelaide Ames (1922) and the second was Payne.

After her doctorate, Payne studied stars of high luminosity in order to understand the structure of the Milky Way. Later she surveyed all the stars brighter than the tenth magnitude. She then studied variable stars, making over 1,250,000 observations with her assistants. This work later was extended to the Magellanic Clouds, adding a further 2,000,000 observations of variable stars. These data were used to determine the paths of stellar evolution. Her observations and analysis, with her husband, of variable stars laid the basis for all subsequent work on them.

Payne-Gaposchkin remained scientifically active throughout her life, spending her entire academic career at Harvard. At first, she had no official position, merely serving as a technical assistant to Shapley from 1927 to 1938. At one point she considered leaving Harvard because of her low status and poor salary. However, Shapley made efforts to improve her position, and in 1938 she was given the title of “Astronomer”. She later asked to have this title changed to Phillips Astronomer. None of the courses she taught at Harvard were recorded in the catalogue until 1945.

When Donald Menzel became Director of the Harvard College Observatory in 1954, he tried to improve her appointment, and in 1956 she became the first woman to be promoted to full professor from within the faculty at Harvard’s Faculty of Arts and Sciences. Later, with her appointment to the Chair of the Department of Astronomy, she also became the first woman to head a department at Harvard.

Her students included Helen Sawyer Hogg, Joseph Ashbrook, Frank Drake and Paul W. Hodge, who all made important contributions to astronomy. She also supervised Frank Kameny, who became a prominent advocate of gay rights.

Payne-Gaposchkin retired from active teaching in 1966 and was subsequently appointed Emeritus Professor of Harvard. She continued her research as a member of staff at the Smithsonian Astrophysical Observatory.

 

 

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The real time machine

Cosmic Look-Back Time

The finite speed of light means that we must always be out of date, no matter how hard we strive to keep up with the times. Thus, the seemingly simple question – what is happening right now on the Sun? – cannot be answered by an observer on Earth, because it takes light 8 minutes to reach Earth from the Sun.

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Humanism Secular

Secular humanism

The philosophy or life stance of secular humanism (alternatively known by some adherents as Humanism, specifically with a capital H to distinguish it from other forms of humanism) embraces human reason, ethics, social justice and philosophical naturalism, while specifically rejecting religious dogma, supernaturalism, pseudoscience or superstition as the basis of morality and decision making.

It posits that human beings are capable of being ethical and moral without religion or a god. It does not, however, assume that humans are either inherently evil or innately good, nor does it present humans as being superior to nature. Rather, the humanist life stance emphasizes the unique responsibility facing humanity and the ethical consequences of human decisions.

Fundamental to the concept of secular humanism is the strongly held viewpoint that ideology—be it religious or political—must be thoroughly examined by each individual and not simply accepted or rejected on faith. Along with this, an essential part of secular humanism is a continually adapting search for truth, primarily through science and philosophy. Many Humanists derive their moral codes from a philosophy of utilitarianism, ethical naturalism or evolutionary ethics, and some advocate a science of morality.

The International Humanist and Ethical Union (IHEU) is the world union of more than one hundred Humanist, rationalist, irreligious, atheistic, Bright, secular, Ethical Culture, and freethought organizations in more than 40 countries. The “Happy Human” is the official symbol of the IHEU as well as being regarded as a universally recognised symbol for those who call themselves Humanists. Secular humanist organizations are found in all parts of the world. Those who call themselves humanists are estimated to number between four and five million people worldwide.

Terminology

The meaning of the phrase secular humanism has evolved over time. The phrase has been used since at least the 1930s, and in 1943, the then Archbishop of Canterbury, William Temple, was reported as warning that the “Christian tradition… was in danger of being undermined by a ‘Secular Humanism’ which hoped to retain Christian values without Christian faith.” During the 1960s and 1970s the term was embraced by some humanists who considered themselves anti-religious, as well as those who, although not critical of religion in its various guises, preferred a non-religious approach. The release in 1980 of A Secular Humanist Declaration by the newly formed Council for Democratic and Secular Humanism (CODESH, now the Council for Secular Humanism) gave secular humanism an organisational identity within the United States.

 

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Humanist?

However, many adherents of the approach reject the use of the word secular as obfuscating and confusing, and consider that the term secular humanism has been “demonized by the religious right… All too often secular humanism is reduced to a sterile outlook consisting of little more than secularism slightly broadened by academic ethics. This kind of ‘hyphenated humanism’ easily becomes more about the adjective than its referent”.

Adherents of this view, including the International Humanist and Ethical Union and the American Humanist Association, consider that the unmodified but capitalised word Humanism should be used. The endorsement by the IHEU of the capitalization of the word Humanism, and the dropping of any adjective such as secular, is quite recent.

The American Humanist Association began to adopt this view in 1973, and the IHEU formally endorsed the position in 1989. In 2002 the IHEU General Assembly unanimously adopted the Amsterdam Declaration, which represents the official defining statement of World Humanism for Humanists.

This declaration makes exclusive use of capitalized Humanist and Humanism, which is consistent with IHEU’s general practice and recommendations for promoting a unified Humanist identity. To further promote Humanist identity, these words are also free of any adjectives, as recommended by prominent members of IHEU. Such usage is not universal among IHEU member organizations, though most of them do observe these conventions.

 

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Age of the Universe

Age of the Universe – Since The Big Bang?

In physical cosmology, the age of the universe is the time elapsed since the Big Bang. The best measurement of the age of the universe is 13.798±0.037 billion years ((13.798±0.037)×109 years or (4.354±0.012)×1017 seconds) within the Lambda-CDM concordance model.

 

 

The uncertainty of 37 million years has been obtained by the agreement of a number of scientific research projects, such as microwave background radiation measurements by the Planck satellite, the Wilkinson Microwave Anisotropy Probe and other probes.

 

 

Measurements of the cosmic background radiation give the cooling time of the universe since the Big Bang, and measurements of the expansion rate of the universe can be used to calculate its approximate age by extrapolating backwards in time.

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Supernova light curves

Supernova Superlight Sight

The visual light curves of the different supernova types vary in shape and amplitude, based on the underlying mechanisms of the explosion, the way that visible radiation is produced, and the transparency of the ejected material. The light curves can be significantly different at other wavelengths. For example, at UV and shorter wavelengths there is an extremely luminous peak lasting just a few hours, corresponding to the shock breakout of the initial explosion, which is hardly detectable at longer wavelengths.

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The light curves for type Ia are mostly very uniform, with a consistent maximum absolute magnitude and a relatively steep decline in luminosity. The energy output is driven by radioactive decay of nickel-56 (half life 6 days), which then decays to radioactive cobalt-56 (half life 77 days). These radioisotopes from material ejected in the explosion excite surrounding material to incandescence.

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The initial phases of the light curve decline steeply as the effective size of the photosphere decreases and trapped electromagnetic radiation is depleted. The light curve continues to decline in the B band while it may show a small shoulder in the visual at about 40 days, but this is only a hint of a secondary maximum that occurs in the infra-red as certain ionised heavy elements recombine to produce infra-red radiation and the ejecta become transparent to it.

The visual light curve continues to decline at a rate slightly greater than the decay rate of the radioactive cobalt (which has the longer half life and controls the later curve), because the ejected material becomes more diffuse and less able to convert the high energy radiation into visual radiation. After several months, the light curve changes its decline rate again as positron emission becomes dominant from the remaining cobalt-56, although this portion of the light curve has been little-studied.
Type Ib and Ic light curves are basically similar to type Ia although with a lower average peak luminosity. The visual light output is again due to radioactive decay being converted into visual radiation, but there is a much lower mass of nickel-56 produced in these types of explosion. The peak luminosity varies considerably and there are even occasional type Ib/c supernovae orders of magnitude more and less luminous than the norm.

The most luminous type Ic supernovae are referred to as hypernovae and tend to have broadened light curves in addition to the increases peak luminosity. The source of the extra energy is thought to be relativistic jets driven by the formation of a rotating black hole, which also produce gamma-ray bursts.

 

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Supernova Discovery

History and Observation of the Supernova

Early work on what was originally believed to be simply a new category of novae was performed during the 1930s by Walter Baade and Fritz Zwicky at Mount Wilson Observatory. The name super-novae was first used during 1931 lectures held at Caltech by Baade and Zwicky, then used publicly in 1933 at a meeting of the American Physical Society.

By 1938, the hyphen had been lost and the modern name was in use. Because supernovae are relatively rare events within a galaxy, occurring about three times a century in the Milky Way, obtaining a good sample of supernovae to study requires regular monitoring of many galaxies.

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Crab Nebula

Supernovae in other galaxies cannot be predicted with any meaningful accuracy. Normally, when they are discovered, they are already in progress. Most scientific interest in supernovae—as standard candles for measuring distance, for example—require an observation of their peak luminosity. It is therefore important to discover them well before they reach their maximum. Amateur astronomers, who greatly outnumber professional astronomers, have played an important role in finding supernovae, typically by looking at some of the closer galaxies through an optical telescope and comparing them to earlier photographs.

Toward the end of the 20th century astronomers increasingly turned to computer-controlled telescopes and CCDs for hunting supernovae. While such systems are popular with amateurs, there are also professional installations such as the Katzman Automatic Imaging Telescope. Recently the Supernova Early Warning System (SNEWS) project has begun using a network of neutrino detectors to give early warning of a supernova in the Milky Way galaxy. Neutrinos are particles that are produced in great quantities by a supernova explosion, and they are not significantly absorbed by the interstellar gas and dust of the galactic disk.

Hipparchus’ interest in the fixed stars may have been inspired by the observation of a supernova (according to Pliny). The earliest recorded supernova, SN 185, was viewed by Chinese astronomers in 185 AD. The brightest recorded supernova was the SN 1006, which was described in detail by Chinese and Islamic astronomers. The widely observed supernova SN 1054 produced the Crab Nebula. Supernovae SN 1572 and SN 1604, the latest to be observed with the naked eye in the Milky Way galaxy, had notable effects on the development of astronomy in Europe because they were used to argue against the Aristotelian idea that the universe beyond the Moon and planets was immutable. Johannes Kepler began observing SN 1604 on October 17, 1604. It was the second supernova to be observed in a generation (after SN 1572 seen by Tycho Brahe in Cassiopeia).

Since the development of the telescope, the field of supernova discovery has extended to other galaxies, starting with the 1885 observation of supernova S Andromedae in the Andromeda galaxy. American astronomers Rudolph Minkowski and Fritz Zwicky developed the modern supernova classification scheme beginning in 1941. In the 1960s, astronomers found that the maximum intensities of supernova explosions could be used as standard candles, hence indicators of astronomical distances. Some of the most distant supernovae recently observed appeared dimmer than expected.

This supports the view that the expansion of the universe is accelerating. Techniques were developed for reconstructing supernova explosions that have no written records of being observed. The date of the Cassiopeia A supernova event was determined from light echoes off nebulae, while the age of supernova remnant RX J0852.0-4622 was estimated from temperature measurements and the gamma ray emissions from the decay of titanium-44. In 2009, nitrates were discovered in Antarctic ice deposits that matched the times of past supernova events.

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the causes and symptons of emphysema

Adapt-logoWhat is Alpha-1 Antitrypsin Deficiency?

Alpha-1 Antitrypsin Deficiency also known as Alpha-1, A1AD or AATD is an inherited, genetic condition that is passed on from generation to generation. As the name suggests it is a deficiency of alpha-1 antitrypsin (AAT) in the bloodstream. AAT is an enzyme produced in the liver to help protect the tissues of the body during infections.

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Alpha-1

The low level of AAT in the blood occurs because the AAT is abnormal and cannot be released from the liver at the normal rate. This leads to a build up of abnormal AAT in the liver that can cause liver disease and a decrease of AAT in the blood that can lead to lung disease.

What is ADAPT?

ADAPT (Antitrypsin Deficiency Assessment and Programme for Treatment) has been established by research doctors who have an international reputation for their research into the causes of emphysema, in collaboration with the pharmaceutical company Bayer.

ADAPT’s mission is to rapidly collect important information about how AAT deficiency affects you and your family. In addition to being helpful to you in understanding the effects of AAT deficiency on your lungs, this information will be critical to the design of clinical studies of the effects of treatment of the disease.
Finally, ADAPT will provide an information service to you and your relatives to explain how AAT deficiency influences you, your health, and your lifestyle.

Alpha-1-4cure

 

 

 

 

 

 

 

 

 
 

 

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Latest hubble april25th

Hubble Space Telescope

Astronomical Forensics Uncover Planetary Disks in NASA’s Hubble Archive

Astronomers using NASA’s Hubble Space Telescope have applied a new image processing technique to obtain near-infrared scattered light photos of five disks observed

around young stars in the Mikulski Archive for Space Telescopes database. These disks are telltale evidence for newly formed planets.

If astronomers initially miss something in their review of data, they can make new discoveries by revisiting earlier data with new image processing techniques, thanks to the wealth

of information stored in the Hubble data archive. This is what Rémi Soummer, of the Space Telescope Science Institute (STScI) in Baltimore, Md., and his team recently did while

on a hunt for hidden Hubble treasures.

The stars in question initially were targeted with Hubble’s Near Infrared Camera and Multi-Object Spectrometer (NICMOS) based on unusual heat signatures obtained from

NASA’s Spitzer Space Telescope and the Infrared Astronomical Satellite that flew in 1983. The previous data provided interesting clues that dusty disks could exist around these

stars. Small dust particles in the disks might scatter light and therefore make the disks visible. But when Hubble first viewed the stars between 1999 and 2006, no disks weredetected in the NICMOS pictures

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Mars is Cool!

mars in solar system orbit

Mars Orbit

It’s the Rock ‘n Roll Planet

Mars has approximately half the diameter of Earth. It is less dense than Earth, having about 15% of Earth’s volume and 11% of the mass. Its surface area is only slightly less than the total area of Earth’s dry land. While Mars is larger and more massive than Mercury, Mercury has a higher density.

This results in the two planets having a nearly identical gravitational pull at the surface – that of Mars is stronger by less than 1%.

The red-orange appearance of the Martian surface is caused by iron(III) oxide, more commonly known as hematite, or rust. It can also look butterscotch, and other common surface colors include golden, brown, tan, and greenish, depending on minerals.

 

 

 

 

 

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It’s All Within Orion

A detailed list of the contents within Orion.

Orion is a prominent constellation located on the celestial equator and visible throughout the world. It is one of the most conspicuous and recognizable constellations in the night sky. It was named after Orion, a hunter in Greek mythology. Its brightest stars are Rigel (Beta Orionis) and Betelgeuse (Alpha Orionis), a blue-white and a red supergiant respectively. Many of the other brighter stars in the constellation are hot, blue supergiant stars. The three stars in the middle of the constellation form an asterism known as Orion’s belt. The Orion Nebula is located south of Orion’s belt.

Stars

  • Betelgeuse, known alternatively by its Bayer designation Alpha Orionis, is a massive M-type red supergiant star nearing the end of its life. When it explodes it will even be visible during the day. It is the second brightest star in Orion, and is a semiregular variable star. It serves as the “right shoulder” of the hunter it represents (assuming that he is facing the observer), and is the eighth brightest star in the night sky.
  • Rigel, which is also known as Beta Orionis, is a B-type blue supergiant that is the sixth brightest star in the night sky. Similar to Betelgeuse, Rigel is fusingheavy elements in its core and will pass its supergiant stage soon (on an astronomical timescale), either collapsing in the case of a supernova or shedding its outer layers and turning into a white dwarf. It serves as the left foot of Orion, the hunter.
  • Bellatrix was designated Gamma Orionis by Johann Bayer, but is known colloquially as the “Amazon Star”. It is the twenty-seventh brightest star in the night sky. Bellatrix is considered a B-type blue giant, though it is too small to explode in a supernova. Bellatrix’s luminosity is derived from its high temperature rather than its radius, a factor that defines Betelgeuse. Bellatrix serves as Orion’s left shoulder.
  • Mintaka garnered the name Delta Orionis from Bayer, even though it is the faintest of the three stars in Orion’s Belt. Its name means “the Giant’s belt”. It is a multiple star system, composed of a large B-type blue giant and a more massive O-type white star. The Mintaka system constitutes an eclipsing binary variable star, where the eclipse of one star over the other creates a dip in brightness. Mintaka is the westernmost of the three stars of Orion’s Belt, as well as the northernmost.
  • Alnilam is designated Epsilon Orionis, a consequence of Bayer’s wish to name the three stars in Orion’s Belt (from north to south) in alphabetical order. Also called Al Nathin, Alnilam is named for the Arabic phrase meaning “string of pearls”. Alnilam is a B-type blue supergiant; despite being nearly twice as far from the Sun as Mintaka and Alnitak, the other two belt stars, its luminosity makes it nearly equal in magnitude. Alnilam is losing mass quickly, a consequence of its size; it is approximately four million years old.
  • Alnitak, meaning “the girdle”,was designated Zeta Orionis by Bayer, and is the easternmost star in Orion’s Belt. It is a triple star some 800 light years distant, with the primary star being a hot blue supergiant and the brightest class Ostar in the night sky.
  • Saiph was designated Kappa Orionis by Bayer, and serves as Orion’s right foot. It is of a similar distance and size to Rigel, but appears much fainter, as its hot surface temperature (46,000°F or 26,000°C) causes it to emit most of its light in the ultraviolet region of the spectrum.

Of the lesser stars, Hatsya (or Iota Orionis) forms the tip of Orion’s sword, whilst Meissa (or Lambda Orionis) forms Orion’s head. Iota Orionis is also called Nair al-Saif, Arabic for “the brightest in the sword”.

Orion’s Belt

Hanging from Orion’s belt is his sword, consisting of the multiple stars θ1 and θ2 Orionis, called the Trapezium and the Orion Nebula (M42). This is a spectacular object that can be clearly identified with the naked eye as something other than a star. Using binoculars, its clouds of nascent stars, luminous gas, and dust can be observed. The Trapezium cluster has many newborn stars, including several brown dwarfs, all of which are at an approximate distance of 1,500 light-years. Named for the four bright stars that form a trapezoid, it is largely illuminated by the brightest stars, which are only a few hundred thousand years old. Observations by the Chandra X-ray Observatory show both the extreme temperatures of the main stars—up to 60,000 Kelvin—and the star forming regions still extant in the surrounding nebula.

M78 (NGC 2068) is a nebula in Orion. With an overall magnitude of 8.0, it is significantly dimmer than the Great Orion Nebula that lies to its south; however, it is at approximately the same distance, at 1600 light-years from Earth. It can easily be mistaken for a comet in the eyepiece of a telescope. M78 is associated with the variable starV351 Orionis, whose magnitude changes are visible in very short periods of time. Another fairly bright nebula in Orion is NGC 1999, also close to the Great Orion Nebula. It has an integrated magnitude of 10.5 and is 1500 light-years from Earth. The variable star V380 Orionis is embedded in NGC 1999.

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Orion Constellation

 

Another famous nebula is IC 434, the Horsehead Nebula, near ζ Orionis. It contains a dark dust cloud whose shape gives the nebula its name.

Besides these nebulae, surveying Orion with a small telescope will reveal a wealth of interesting deep-sky objects, including M43, M78, as well as multiple stars including Iota Orionis and Sigma Orionis. A larger telescope may reveal objects such as Barnard’s Loop and the Flame Nebula (NGC 2024), as well as fainter and tighter multiple stars and nebulae.

All of these nebulae are part of the larger Orion Molecular Cloud Complex, which is located approximately 1,500 light-years away and is hundreds of light-years across. It is one of the most intense regions of stellar formation visible in our galaxy.

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Infrared In Astronomy

Infrared astronomy is the branch of astronomy and astrophysics that studies astronomical objects visible in infrared (IR) radiation. The wavelength of infrared light ranges from 0.75 to 300 micrometers. Infrared falls in between visible radiation, which ranges from 380 to 750 nanometers, and submillimeter waves.

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Emission Neb Head

Infrared astronomy began in the 1830s, a few decades after the discovery of infrared light by William Herschel in 1800. Early progress was limited, and it was not until the early 20th century that conclusive detections of astronomical objects other than the Sun and Moon were detected in infrared light. After a number of discoveries were made in the 1950s and 1960s in radio astronomyastronomers realized the information available outside of the visible wavelength range, and modern infrared astronomy was established.

Infrared and optical astronomy are often practiced using the same telescopes, as the same mirrors or lenses are usually effective over a wavelength range that includes both visible and infrared light. Both fields also use solid state detectors, though the specific type of solid state detectors used are different. Infrared light is absorbed at many wavelengths by water vapor in the Earth’s atmosphere, so most infrared telescopes are at high elevations in dry places, above as much of the atmosphere as possible. There are also infrared observatories in space, including the Spitzer Space Telescope and the Herschel Space Observatory.

 

The discovery of infrared radiation is attributed to William Herschel, who performed an experiment where he placed a thermometer in sunlight of different colors after it passed through a prism. He noticed that the temperature increase induced by sunlight was highest outside the visible spectrum, just beyond the red color. That the temperature increase was highest at infrared wavelengths was due to the spectral index of the prism rather than properties of the Sun, but the fact that there was any temperature increase at all prompted Herschel to deduce that there was invisible radiation from the Sun. He dubbed this radiation “calorific rays”, and went on to show that it could be reflected, transmitted, and absorbed just like visible light.

Efforts were made starting in the 1830s and continuing through the 19th century to detect infrared radiation from other astronomical sources. Radiation from the Moon was first detected in 1873 by William Parsons, 3rd Earl of RosseErnest Fox Nichols used a modified Crookes radiometer in an attempt to detect infrared radiation from Arcturus and Vega, but Nichols deemed the results inconclusive. Even so, the ratio of flux he reported for the two stars is consistent with the modern value, so George Rieke gives Nichols credit for the first detection of a star other than our own in the infrared.

The field of infrared astronomy continued to develop slowly in the early 20th century, as Seth Barnes Nicholson and Edison Pettit developed thermopile detectors capable of accurate infrared photometry and sensitive to a few hundreds of stars. The field was mostly neglected by traditional astronomers though until the 1960s, with most scientists who practiced infrared astronomy having actually been trained physicists. The success of radio astronomy during the 1950s and 1960s, combined with the improvement of infrared detector technology, prompted more astronomers to take notice, and infrared astronomy became well established as a subfield of astronomy.

 

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Use Command Prompt To Check Windows System Files

Run the System File Checker tool (SFC.exe)

You can use the program by just right-clicking the hard drive icon (usually the C:Drive) and looking under “tools”. For a more thorough check though, try using the Command Prompt option.

Windows 7 or Windows Vista To do this, click Start, type Command Prompt or cmd in the Search box, right-click Command Prompt, and then click Run as administrator.

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Run as Admin

 

If you are prompted for an administrator password or for a confirmation, type the password, or click Allow.

At the command prompt, type the following command, and then press ENTER:

sfc /scannow

Command_prompt-UI

The sfc /scannow command will scan all protected system files, and replace corrupted files with a cached copy that is located in a compressed folder at %WinDir%\System32\dllcache. The %WinDir% placeholder represents the Windows operating system folder. For example, C:\Windows.

Note Do not close this Command Prompt window until the verification is 100% complete. The scan results will be shown after this process is finished.


After the process is finished, you may receive one of the following messages:

* Windows Resource Protection did not find any integrity violations.

This means that you do not have any missing or corrupted system files.

 * Windows Resource Protection could not perform the requested operation.

 To resolve this problem, perform the System File Checker scan in safe mode, and make sure that the PendingDeletes and PendingRenames folders exist under %WinDir%\WinSxS\Temp.

 * Windows Resource Protection found corrupt files and successfully repaired them. Details are included in the CBS.Log %WinDir%\Logs\CBS\CBS.log.

 To view the detail information about the system file scan and restoration, go to How to view details of the System File Checker process.

 * Windows Resource Protection found corrupt files but was unable to fix some of them. Details are included in the CBS.Log %WinDir%\Logs\CBS\CBS.log.

 

To repair the corrupted files manually, view details of the System File Checker process to find the corrupted file, and then manually replace the corrupted file with a known good copy of the file.

 

 

 

 

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Could It Be A Crunch of An Ending?

The Big Crunch

In physical cosmology, the Big Crunch is one possible scenario for the ultimate fate of the universe, in which the metric expansion of space eventually reverses and the universe collapses, ultimately ending as a black hole singularity or causing a reformation of the universe starting with another big bang. Sudden singularities and crunch or rip singularities at late times occur only for hypothetical matter with implausible physical properties.

If the universe is finite in extent and the cosmological principle (not to be confused with the cosmological constant) does not apply, and the expansion speed does not exceed the escape velocity, then the mutual gravitational attraction of all its matter will eventually cause it to contract. If entropy continues to increase in the contracting phase (see Ergodic hypothesis), the contraction would appear very different from the time reversal of the expansion. While the early universe was highly uniform, a contracting universe would become increasingly clumped. Eventually all matter would collapse into black holes, which would then coalesce producing a unified black hole or Big Crunch singularity.

The Hubble Constant measures the current state of expansion in the universe, and the strength of the gravitational force depends on the density and pressure of the matter and in the universe, or in other words, the critical density of the universe. If the density of the universe is greater than the critical density, then the strength of the gravitational force will stop the universe from expanding and the universe will collapse back on itself—assuming that there is no repulsive force such as a cosmological constant.

Conversely, if the density of the universe is less than the critical density, the universe will continue to expand and the gravitational pull will not be enough to stop the universe from expanding. This scenario would result in the ‘Big Freeze’, where the universe cools as it expands and reaches a state of entropy. One theory proposes that the universe could collapse to the state where it began and then initiate another Big Bang, so in this way the universe would last forever, but would pass through phases of expansion (Big Bang) and contraction (Big Crunch).

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We all crunch together.

Recent experimental evidence (namely the observation of distant supernovae as standard candles, and the well-resolved mapping of the cosmic microwave background) has led to speculation that the expansion of the universe is not being slowed down by gravity but rather accelerating.

 

 

 

However, since the nature of the dark energy that is postulated to drive the acceleration is unknown, it is still possible (though not observationally supported as of today) that it might eventually reverse sign and cause a collapse.

 

 

 

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The universe is much bigger than the observable universe post I did yesterday

Some parts of the universe may simply be too far away – an under-statement maybe too…

Some parts of the universe may simply be too far away for the light emitted from there at any moment since the Big Bang to have had enough time to reach Earth at present, so these portions of the universe would currently lie outside the observable universe.

In the future, light from distant galaxies will have had more time to travel, so some regions not currently observable will become observable. However, due to Hubble’s law regions sufficiently distant from us are expanding away from us much faster than the speed of light (special relativity prevents nearby objects in the same local region from moving faster than the speed of light with respect to each other, but there is no such constraint for distant objects when the space between them is expanding; see uses of the proper distance for a discussion), and the expansion rate appears to be accelerating due to dark energy.

Assuming dark energy remains constant (an unchanging cosmological constant), so that the expansion rate of the universe continues to accelerate, there is a “future visibility limit” beyond which objects will never enter our observable universe at any time in the infinite future, because light emitted by objects outside that limit would never reach us. (A subtlety is that, because the Hubble parameter is decreasing with time, there can be cases where a galaxy that is receding from us just a bit faster than light does emit a signal that reaches us eventually).

This future visibility limit is calculated at a comoving distance of 19 billion parsecs (62 billion light years) assuming the universe will keep expanding forever, which implies the number of galaxies that we can ever theoretically observe in the infinite future (leaving aside the issue that some may be impossible to observe in practice due to redshift, as discussed in the following paragraph) is only larger than the number currently observable by a factor of 2.36.

Some parts of the universe may simply be too far away for the light emitted from there at any moment since the Big Bang to have had enough time to reach Earth at present, so these portions of the universe would currently lie outside the observable universe. In the future, light from distant galaxies will have had more time to travel, so some regions not currently observable will become observable. However, due to Hubble’s law regions sufficiently distant from us are expanding away from us much faster than the speed of light (special relativity prevents nearby objects in the same local region from moving faster than the speed of light with respect to each other, but there is no such constraint for distant objects when the space between them is expanding; see uses of the proper distance for a discussion), and the expansion rate appears to be accelerating due to dark energy.

Assuming dark energy remains constant (an unchanging cosmological constant), so that the expansion rate of the universe continues to accelerate, there is a “future visibility limit” beyond which objects will never enter our observable universe at any time in the infinite future, because light emitted by objects outside that limit would never reach us. (A subtlety is that, because the Hubble parameter is decreasing with time, there can be cases where a galaxy that is receding from us just a bit faster than light does emit a signal that reaches us eventually).

This future visibility limit is calculated at a comoving distance of 19 billion parsecs (62 billion light years) assuming the universe will keep expanding forever, which implies the number of galaxies that we can ever theoretically observe in the infinite future (leaving aside the issue that some may be impossible to observe in practice due to redshift, as discussed in the following paragraph) is only larger than the number currently observable by a factor of 2.36.

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The Observable Universe – From Earth

 

The observable universe consists of the galaxies and other matter that can, in principle, be observed from Earth in the present day because light (or other signals) from those objects has had time to reach the Earth since the beginning of the cosmological expansion. Assuming the universe is isotropic, the distance to the edge of the observable universe is roughly the same in every direction. That is, the observable universe is a spherical volume (a ball) centered on the observer, regardless of the shape of the universe as a whole. Every location in the universe has its own observable universe, which may or may not overlap with the one centered on Earth.

The diameter of the observable universe is estimated at about 28 billion parsecs (93 billion light-years), putting the edge of the observable universe at about 46–47 billion light-years away.

The word observable used in this sense does not depend on whether modern technology actually permits detection of radiation from an object in this region (or indeed on whether there is any radiation to detect). It simply indicates that it is possible in principle for light or other signals from the object to reach an observer on Earth. In practice, we can see light only from as far back as the time of photon decoupling in the recombination epoch. That is when particles were first able to emit photons that were not quickly re-absorbed by other particles. Before then, the universe was filled with a plasma that was opaque to photons.

The surface of last scattering is the collection of points in space at the exact distance that photons from the time of photon decoupling just reach us today. These are the photons we detect today as cosmic microwave background radiation (CMBR). However, with future technology, it may be possible to observe the still older neutrino background, or even more distant events via gravitational waves (which also should move at the speed of light). Sometimes astrophysicists distinguish between the visible universe, which includes only signals emitted since recombination—and the observable universe, which includes signals since the beginning of the cosmological expansion (the Big Bang in traditional cosmology, the end of the inflationary epoch in modern cosmology). According to calculations, the comoving distance (current proper distance) to particles from the CMBR, which represent the radius of the visible universe, is about 14.0 billion parsecs (about 45.7 billion light years), while the comoving distance to the edge of the observable universe is about 14.3 billion parsecs (about 46.6 billion light years), about 2% larger.

 

The best estimate of the age of the universe as of 2013 is 13.798 ± 0.037 billion years but due to the expansion of space humans are observing objects that were originally much closer but are now considerably farther away (as defined in terms of cosmological proper distance, which is equal to the comoving distance at the present time) than a static 13.8 billion light-years distance. The diameter of the observable universe is estimated at about 28 billion parsecs (93 billion light-years), putting the edge of the observable universe at about 46–47 billion light-years away.

 

 

 

 

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Stars in Aries

Constellation Star Features

Aries has three prominent stars forming an asterism, designated Alpha, Beta, and Gamma Arietis by Johann Bayer. All three are commonly used for navigation. There is also one other star above the fourth magnitude, 41 Arietis. α Arietis, called Hamal, is the brightest star in Aries. Its traditional name is derived from the Arabic word for “lamb” or “head of the ram” (ras al-hamal), which references Aries’s mythological background. With a spectral class of K2 and a luminosity class of III, it is an orange giant with an apparent visual magnitude of 2.00, which lies 66 light-years from Earth. Hamal has a luminosity of 96 L and its absolute magnitude is −0.1.

β Arietis, also known as Sheratan, is a blue-white star with an apparent visual magnitude of 2.64. Its traditional name is derived from “sharatayn“, the Arabic word for “the two signs”, referring to both Beta and Gamma Arietis in their position as heralds of the vernal equinox. The two stars were known to the Bedouin as “qarna al-hamal“, “horns of the ram”. It is 59 light-years from Earth. It has a luminosity of 11 L and its absolute magnitude is 2.1. It is a spectroscopic binary star, one in which the companion star is only known through analysis of the spectra. The spectral class of the primary is A5. Hermann Carl Vogel determined that Sheratan was a spectroscopic binary in 1903; its orbit was determined by Hans Ludendorff in 1907. It has since been studied for its eccentric orbit.

γ Arietis, with a common name of Mesarthim, is a binary star with two white-hued components, located in a rich field of magnitude 8–12 stars. Its traditional name has conflicting derivations. It may be derived from a corruption of “al-sharatan”, the Arabic word meaning “pair” or a word for “fat ram”.However, it may also come from the Sanskrit for “first star of Aries” or the Hebrew for “ministerial servants”, both of which are unusual languages of origin for star names. Along with Beta Arietis, it was known to the Bedouin as “qarna al-hamal“. The primary is of magnitude 4.59 and the secondary is of magnitude 4.68. The system is 164 light-years from Earth. The two components are separated by 7.8 arcseconds. The whole system as a whole has an apparent magnitude of 3.9. The primary has a luminosity of 60 L and the secondary has a luminosity of 56 L; the primary is an A-type star with an absolute magnitude of 0.2 and the secondary is a B9-type star with an absolute magnitude of 0.4. The angle between the two components is 1°. Mesarthim was discovered to be a double star by Robert Hooke in 1664, one of the earliest such telescopic discoveries. The primary, γ1 Arietis, is an Alpha² Canum Venaticorum variable star that has a range of 0.02 magnitudes and a period of 2.607 days. It is unusual because of its strong silicon emission lines.

The constellation is home to several double stars, including Epsilon, Lambda, and Pi Arietis. ε Arietis is a binary star with two white components. The primary is of magnitude 5.2 and the secondary is of magnitude 5.5. The system is 290 light-years from Earth. Its overall magnitude is 4.63, and the primary has an absolute magnitude of 1.4. Its spectral class is A2. The two components are separated by 1.5 arcseconds. λ Arietis is a wide double star with a white-hued primary and a yellow-hued secondary. The primary is of magnitude 4.8 and the secondary is of magnitude 7.3. The primary is 129 light-years from Earth. It has an absolute magnitude of 1.7 and a spectral class of F0. The two components are separated by 36 arcseconds at an angle of 50°; the two stars are located 0.5° east of 7 Arietis. π Arietis is a close binary star with a blue-white primary and a white secondary. The primary is of magnitude 5.3 and the secondary is of magnitude 8.5. The primary is 776 light-years from Earth. The primary itself is a wide double star with a separation of 25.2 arcseconds; the tertiary has a magnitude of 10.8. The primary and secondary are separated by 3.2 arcseconds.

Most of the other stars in Aries visible to the naked eye have magnitudes between 3 and 5. δ Ari, called Boteïn, is a star of magnitude 4.35, 170 light-years away. It has an absolute magnitude of −0.1 and a spectral class of K2. ζ Arietis is a star of magnitude 4.89, 263 light-years away. Its spectral class is A0 and its absolute magnitude is 0.0. 14 Arietis is a star of magnitude 4.98, 288 light-years away. Its spectral class is F2 and its absolute magnitude is 0.6. 39 Arietis is a similar star of magnitude 4.51, 172 light-years away. Its spectral class is K1 and its absolute magnitude is 0.0. 35 Arietis is a dim star of magnitude 4.55, 343 light-years away. Its spectral class is B3 and its absolute magnitude is −1.7. 41 Arietis, known both as c Arietis and Nair al Butain, is a brighter star of magnitude 3.63, 165 light-years away. Its spectral class is B8 and it has a luminosity of 105 L. Its absolute magnitude is −0.2. 53 Arietis is arunaway star of magnitude 6.09, 815 light-years away. Its spectral class is B2. It was likely ejected from the Orion Nebula approximately five million years ago, possibly due tosupernovae. Finally, Teegarden’s Star is the closest star to Earth in Aries. It is a brown dwarf of magnitude 15.14 and spectral class M6.5V. With a proper motion of 5.1 arcseconds per year, it is the 24th closest star to Earth overall.

Aries has its share of variable stars, including R and U Arietis, Mira-type variable stars, and T Arietis, a semi-regular variable star. R Arietis is a Mira variable star that ranges in magnitude from a minimum of 13.7 to a maximum of 7.4 with a period of 186.8 days. It is 4,080 light-years away. U Arietis is another Mira variable star that ranges in magnitude from a minimum of 15.2 to a maximum of 7.2 with a period of 371.1 days. T Arietis is a semiregular variable star that ranges in magnitude from a minimum of 11.3 to a maximum of 7.5 with a period of 317 days. It is 1,630 light-years away. One particularly interesting variable in Aries is SX Arietis, a rotating variable star considered to be the prototype of its class, helium variable stars. SX Arietis stars have very prominent emission lines of Helium I and Silicon III. They are normally main-sequence B0p—B9p stars, and their variations are not usually visible to the naked eye. Therefore, they are observed photometrically, usually having periods that fit in the course of one night. Similar to Alpha² Canum Venaticorum variables, SX Arietis stars have periodic changes in their light and magnetic field, which correspond to the periodic rotation; they differ from the Alpha² Canum Venaticorum variables in their higher temperature. There are between 39 and 49 SX Arietis variable stars currently known; ten are noted as being “uncertain” in the General Catalog of Variable Stars

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Pseudoscience

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Pseudoscience is a claim, belief, or practice which is presented as scientific, but does not adhere to a valid scientific method, lacks supporting evidence or plausibility, cannot be reliably tested, or otherwise lacks scientific status.

Pseudoscience is often characterized by the use of vague, contradictory, exaggerated or unprovable claims, an over-reliance on confirmation rather than rigorous attempts at refutation, a lack of openness to evaluation by other experts, and a general absence of systematic processes to rationally develop theories.

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The Aries Constellation

Aries is one of the constellations of the zodiac. It is located in the northern celestial hemisphere between Pisces to the west and Taurus to the east. The name Aries is Latin for ram, and its symbol is  (Unicode ♈), representing a ram’s horns.

It is one of the 48 constellations described by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations. It is a mid-sized constellation, ranking 39th overall size, with an area of 441 square degrees (1.1% of the celestial sphere).

Although Aries came to represent specifically the ram whose fleece became the Golden Fleece of Ancient Greek mythology, it has represented a ram since late Babylonian times. Before that, the stars of Aries formed a farmhand. Different cultures have incorporated the stars of Aries into different constellations including twin inspectors in China and a porpoise in the Marshall Islands. Aries is a relatively dim constellation, possessing only four bright stars: Hamal (Alpha Arietis, second magnitude), Sheratan (Beta Arietis, third magnitude), Mesarthim (Gamma Arietis, fourth magnitude), and 41 Arietis (also fourth magnitude). The few deep-sky objects within the constellation are quite faint and include several pairs of interacting galaxies. Several meteor showers appear to radiate from Aries, including the Daytime Arietids and the Epsilon Arietids.

Img-Aries-naked eye view

Aries – In Naked Naked Eye View

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Cepheus Constellation

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Cepheus Near Polaris

Staring at Cepheus In 2015

The Latest I Have Spotted

The last constellation for my naked eye to see is Cepheus. This has been quite a productive few weeks, I have added a handful of naked-eye view’s to my constellation list. I have also seen Saturn. Very pleased at that – just a shame you can’t see the rings without a telescope!

Cepheus

Cepheus is a constellation in the northern sky. It is named after Cepheus, King of Aethiopia in Greek mythology. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations. Cepheus was the King of Aethiopia. He was married to Cassiopeia and was the father of Andromeda, both of whom are immortalized as modern day constellations along with Cepheus.

Mythology-Cepheus

Cepheusurania

Cepheus son of Agenor is the more well-known Cepheus and the grandson of the other Cepheus. He is featured in the Perseus legend as the husband of lovely Cassiopeia and father of Princess Andromeda, and whose brother Phineus expected to marry Andromeda. When Poseidon sent the sea monster Cetus to attack Aethiopia after his wife boasted that Andromeda was more beautiful than the Nereids, Cepheus and Cassiopeia consulted with a wise oracle who told them to sacrifice Andromeda to Cetus. Cepheus and Cassiopeia had Andromeda chained to a rock near the ocean so that Cetus could devour her. Andromeda was saved from this fate when Perseus arrived and killed Cetus. Cepheus and Cassiopeia allowed Perseus to become Andromeda’s husband after he used Medusa‘s head to turn Phineus and his men to stone.

Cepheus-Coley

Cepheus-Coley

Cepheus was later made into the constellation Cepheus.

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Mythology-constellations

Mythology of the constellation Pegasus

The white, winged horse Pegasus was the offspring of Poseidon and the Gorgon , Medusa, springing from the latter’s neck when she was killed by Perseus. He immediately flew to Mount Helicon and struck the ground with his hoof. The resulting stream which flowed from the spot he had pawed became sacred to the Muses. Some time later Pegasus was to help Perseus to rescue Andromeda from the dreadful sea monster Cetus.
Bellerophon, the grandson of Sisyphus (a selfish man punished by the Gods for his arrogance by being forced to continually push an enormous boulder to the top of a hill, only for it to roll back down just as the goal seemed within reach) was also greatly aided by Pegasus when undertaking several dangerous missions, including his fight against the Chimaera, the three-headed monstrous female. However, the success of this and other missions turned Bellerophon’s head and he, too, became arrogant. So much so, that although a mere mortal, he forced Pegasus to fly him to Mount Olympus, the home of the Gods. Zeus , greatly annoyed at Bellerophon’s presumption that he was worthy to be in such august company, sent an insect to bite Pegasus on his flank, causing him to rear up and throw Bellerophon to the ground. He was then dispatched back to earth, and ended his days a sad and lonely figure, blind and lame. For Pegasus, however, there was the reward of a place in the stables on Mount Olympus, and the opportunity to carry around Zeus’s thunderbolts.

Mythology of the constellation Boötes

BOOTES, The Hunter has since early times been associated with country pursuits – as hunter, ploughman or herdsman. In Homer’s Odyssey he is referred to as Wagoner or Driver of the Wain. However, since the seventeenth century the figure has been associated with the hunting dogs (Canes Venatici) charted by Helvelius.
In Greek legend, Bootes is seen as representing Icarius, an Athenian who was taught the secret of winemaking by the god Dionysius. Icarius then allowed some peasants to sample his produce, but his kindness back-fired. The men became extremely drunk and were convinced that they had been poisoned, so they killed Icarius and buried him. His daughter Erigone and was so overcome with grief when she found his body that she hanged herself. Zeus transferred her to the heavens as Virgo, Icarius became Bootes, and Maera, the dog who had led Erigone to her father’s grave, became one of the dogs of Canes Venatici.
Mythology of the constellation Aquarius

This is the eleventh zodiacal sign and one which has always been connected with water. To the Babylonians it represented an overflowing urn, and they associated this with the heavy rains which fell in their eleventh month, whilst the Egyptians saw the constellation as Hapi, the god of the Nile.
Greek legend, however, tells of Ganymede, an exceptionally handsome, young prince of Troy. He was spotted by Zeus, who immediately decided that he would make a perfect cup-bearer. The story then differs – one version telling how Zeus sent his pet eagle, Aquila, to carry Ganymede to Olympus, another that it was Zeus, himself, disguised as an eagle, who swept up the youth and carried him to the home of the gods. In either case, once Ganymede arrived, he had to contend with the wrath of Hera, wife of Zeus. She was annoyed on two counts – firstly, that her husband should have such strong feelings for a mere boy and, secondly, that Ganymede was to occupy the favoured position previously held by her own daughter Hebe, goddess of youth. But Zeus was not to be thwarted and Ganymede, often riding on Aquila and always carrying the golden cup, accompanied the great god on his travels, impressing him with his kindness. This was made manifest when, realising how in need of water the people on earth were, he pleaded with Zeus to be allowed to help them and was given permission to send down rain. Eventually he was glorified as Aquarius, god of rain, and placed amongst the stars.

Mythology of the constellation Camelopardalis
CAMELOPARDALIS, The Giraffe. is said to represent the Biblical camel which carried Rebecca to Isaac. However, historians are divided as to the inventor of this modern constellation. Some say that Dutchman Petrus Plancius first charted Camelopardalis in 1613, it later being included in Jakob Bartsch’s book on the constellations, whilst others suggest that Bartsch, himself, invented the constellation in 1624.

Mythology of the constellation Coma Berenices

The constellation COMA BERENICES represents the beautiful hair of Queen Berenice of Egypt. She was so concerned for the safety of her husband Ptolemy III when he went off to war, that she vowed to cut off her glorious long hair as a sacrifice to Venus, should he be spared. When he eventually returned safely home, she kept her promise, and Zeus placed her beautiful hair in the heavens to shine among the stars.
Another account suggests that this constellation represents Thisbe’s veil (Legend of Leo).
Mythology of the constellation Cygnus
Many and varied are the myths relating to the naming of the constellation Cygnus, The Swan, some dating back to pre-Greek times, when it was thought that this particular group of stars represented the huge bird “Roc” from the tales of Sinbad the Sailor.
Amongst the many Greek myths relating to Cygnus are that it was once the pet bird of Cassiopeia, or that the constellation represents the murdered Orpheus who was changed into a swan after being murdered by the Thracian women. Two further possibilities are that it was named after either Cionus, Son of Neptune, who was changed into a swan and transported to the heavens by his father in order to prevent him from being smothered by Achilles, or after Cygnus, who tried to save his friend Phaeton, when the latter was struck by one of Zeus’s thunderbolts and hurled into the River Eridanus following his unsuccessful attempt to guide the Sun’s chariot across the heavens.

But possibly the most well known of myths surrounding this constellation is that it represents Zeus in the story of Leda and the swan, Leda being the very beautiful wife of King Tyndareus, of Sparta.
Zeus, noted for his affairs with mortal women, fell in love with Leda and changed himself into a swan in order to seduce her. She produced an egg from which emerged Castor, the mortal son of her husband, and Polydeuces (Pollux), immortal son of Zeus.

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esa huygens probe

Saturn Cassini

The Huygens Probe was named after Christiaan Huygens, a Dutch astronomer who in 1655 discovered Titan, Saturn’s largest moon. The probe was designed by the European Space Agency (ESA), to perform an in-depth study of the clouds, atmosphere, and surface of Titan.

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Spacecraft Orbit – Cassini Saturn

Cassini–Huygens is an unmanned spacecraft sent to the planet Saturn. It is a flagship-class NASA–ESA–ASI robotic spacecraft sent to the Saturn system. It has studied the planet and its many natural satellites since arriving there on June 30, 2004, also observing Jupiter and the heliosphere, and testing the theory of relativity. Launched in 1997 after nearly two decades of development, it includes a Saturn orbiter and an atmospheric probe/lander for the moon Titan called Huygens, which entered and landed on Titan in 2005.

Cassini is the fourth space probe to visit Saturn and the first to enter orbit, and its mission is ongoing as of 2015. The two-part spacecraft is named after astronomers Giovanni Cassini and Christiaan Huygens.

Christiaan Huygens.

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