Unique view is a monumental 108,200 by 81,500 pixel colour image containing nearly nine billion pixels

iIf printed with the resolution of a typical book, it would be 9 metres long and 7 metres tall

A new striking nine-gigapixel image has captured a catalogue of more than 84 million stars in the central parts of the Milky Way - ten times more than previously observed.

It has also found a large number of faint red dwarf stars which are prime candidates around which to search for small exoplanets - planets outside the solar system that may be Earth-like.

This treasure trove of information about the structure and content of the Milky Way is one of the biggest astronomical images ever produced and provides an incredible, zoomable view of the central part of our galaxy and is so large that, if printed with the resolution of a typical book, it would be 9 metres long and 7 metres tall.

To see a fully zoomable version of the new map, click here.

Yet despite its vast size, the image covers just one per cent of the entire sky - about 315 square degrees of the sky.

The Via Lactea survey - the Latin name for the Milky Way - has scanned the southern plane and bulge of the Milky Way since 2010 and has three more years to run.


But so far astronomers have observed about 173 million objects, of which about 84 million have been confirmed as stars.

The other objects were either too faint or blended with their neighbours or affected by other artefacts, so that accurate measurements were not possible. Others were extended objects such as distant galaxies.

Astronomers hope the breakthrough will provide a giant leap forward in our understanding of the universe and was captured by the VISTA infrared survey telescope at the European Southern Observatory's Paranal facility in Chile.

Roberto Saito said: 'By observing in detail the myriads of stars surrounding the centre of the Milky Way we can learn a lot more about the formation and evolution of not only our galaxy, but also spiral galaxies in general.'


Most spiral galaxies, including our home galaxy the Milky Way, have a large concentration of ancient stars surrounding the centre that astronomers call the bulge - and understanding the formation and evolution of the bulge is vital for understanding the galaxy as a whole.

However space dust obscured the bulge of the Milky Way so "to peer into the heart of the galaxy" scientists needed to observe in infrared light which is less affected by the dust.

To help analyse the catalogue the brightness of each star is plotted against its colour for about 84 million stars to create a colour-magnitude diagram which contains more than ten times more stars than any previous study and it is the first time that this has been done for the entire bulge.

It will then allow astronomers to study the different physical properties of stars such as their temperatures, masses and ages.

Fellow researcher Dante Minniti added: 'Each star occupies a particular spot in this diagram at any moment during its lifetime.


'Since the new data gives us a snapshot of all the stars in one go, we can now make a census of all the stars in this part of the Milky Way.'

Source This findings are published in the journal Astronomy & Astrophysics.

Of the 5,000 or so stars brighter than magnitude 6, only a handful of very faint stars are approximately the same size and brightness of our Sun and the rest are all bigger and brighter. Of the 500 or so that are brighter than 4th magnitude (which includes essentially every star visible to the unaided eye from a urban location), all are intrinsically bigger and brighter than our Sun, many by a large percentage. Of the brightest 50 stars visible to the human eye from Earth, the least intrinsically bright is Alpha Centauri, which is still more than 1.5 times more luminous than our Sun, and cannot be easily seen from most of the Northern Hemisphere.

Despite what you may hear in TV commercials, poems and songs, you cannot see a million stars … anywhere. There simply are not enough close enough and bright enough. On a really exceptional night, with no Moon and far from any source of lights, a person with very good eyesight may be able to see 2000-2500 stars at any one time. (Counting even this small number still would be difficult.). So the next time you hear someone claim to have seen a million stars in the sky, just appreciate it as artistic license or exuberant exaggeration – because it isn’t true!

We are accustomed to referring to things that are red as hot and those that are blue as cool. This is not entirely unreasonable, since a red, glowing fireplace poker is hot and ice, especially in glaciers and polar regions, can have a bluish cast. But we say that only because our everyday experience is limited. In fact, heated objects change color as their temperature changes, and red represents the lowest temperature at which a heated object can glow in visible light. As it gets hotter, the color changes to white and ultimately to blue. So the red stars you see in the sky are the “coolest” (least hot), and the blue stars are the hottest!


A black body is an object that absorbs 100 percent of all electromagnetic radiation (that is, light, radio waves and so on) that falls on it. A common image here is that of a brick oven with the interior painted black and the only opening a small window. All light that shines through the window is absorbed by the interior of the oven and none is reflected outside the oven. It is a perfect absorber. As it turns out, this definition of being perfect absorbers suits stars very well! However, this just says that a blackbody absorbs all the radiant energy that hits it, but does not forbid it from re-emitting the energy. In the case of a star, it absorbs all radiation that falls on it, but it also radiates back into space much more than it absorbs. Thus a star is a black body that glows with great brilliance! (An even more perfect black body is a black hole, but of course, it appears truly black, and radiates no light.)

Although there are scattered claims for stars that appear green, including Beta Librae (Zuben Eschamali), most observers do not see green in any stars except as an optical effect from their telescopes, or else an idiosyncratic quirk of personal vision and contrast. Stars emit a spectrum (“rainbow”) of colors, including green, but the human eye-brain connection mixes the colors together in a manner that rarely if ever comes out green. One color can dominate the radiation, but within the range of wavelengths and intensities found in stars, greens get mixed with other colors, and the star appears white. For stars, the general colors are, from lower to higher temperatures, red, orange, yellow, white and blue. So as far as the human eye can tell, there are no green stars.


That being said, the Sun is a “green” star, or more specifically, a green-blue star, whose peak wavelength lies clearly in the transition area on the spectrum between blue and green. This is not just an idle fact, but is important because the temperature of a star is related to the color of its most predominate wavelength of emission. (Whew!) In the Sun’s case, the surface temperature is about 5,800 K, or 500 nanometers, a green-blue. However, as indicated above, when the human eye factors in the other colors around it, the Sun’s apparent color comes out a white or even a yellowish white.


We are accustomed to think of the Sun as a “normal” star, and in many respects, it is. But did you know that it is a “dwarf” star? You may have heard of a “white dwarf,” but that is not a regular star at all, but the corpse of a dead star. Technically, as far as “normal” stars go (that is, astronomical objects that produce their own energy through sustained and stable hydrogen fusion), there are only “dwarfs,” “giants” and “supergiants.” The giants and supergiants represent the terminal (old age) stages of stars, but the vast majority of stars, those in the long, mature stage of evolution (Main Sequence) are all called “dwarfs.” There is quite a bit of range in size here, but they are all much smaller than the giants and supergiants. So technically, the Sun is a dwarf star, sometimes called “Yellow Dwarf” in contradiction to the entry above!

Stars appear to twinkle (“scintillate”), especially when they are near the horizon. One star, Sirius, twinkles, sparkles and flashes so much some times that people actually report it as a UFO. But in fact, the twinkling is not a property of the stars, but of Earth’s turbulent atmosphere. As the light from a star passes through the atmosphere, especially when the star appears near the horizon, it must pass through many layers of often rapidly differing density. This has the effect of deflecting the light slightly as it were a ball in a pinball machine. The light eventually gets to your eyes, but every deflection causes it to change slightly in color and intensity. The result is “twinkling.” Above the Earth’s atmosphere, stars do not twinkle.

On a good night, you can see about 19,000,000,000,000,000 miles, easily. That’s 19 quadrillion miles, the approximate distance to the bright star Deneb in Cygnus. which is prominent in the evening skies of Fall and Winter. Deneb is bright enough to be seen virtually anywhere in the Northern hemisphere, and in fact from almost anywhere in the inhabited world. There is another star, Eta Carina, that is a little more than twice as far away, or about 44 quadrillion miles. But Eta Carina is faint, and not well placed for observers in most of the Northern hemisphere. Those are stars, but both the Andromeda Galaxy and the Triangulum Galaxy are also visible under certain conditions, and are roughly 15 and 18 quintillion miles away! (One quintillion is 10^18!)

Many writers frequently describe black holes as “sucking” in everything around them. And it is a common worry among the ill-informed that the so-far hypothetical “mini” black holes that may be produced by the Large Hadron Collider would suck in everything around them in an ever increasing vortex that would consume the Earth! “Say it ain’t so, Joe!” Well, I am not Shoeless Joe Jackson, but it ain’t so. In the case of the LHC, it isn’t true for a number of reasons, but black holes in general do not “suck.”

This not just a semantic distinction, but one of process and consequence as well. The word “suck” via suction, as in the way vacuum cleaners work, is not how black holes attract matter. In a vacuum cleaner, the fan produces a partial vacuum (really, just a slightly lower pressure) at the floor end of the vacuum, and regular air pressure outside, being greater, pushes the air into it, carrying along loose dirt and dust.

In the case of black holes, there is no suction involved. Instead, matter is pulled into the black hole by a very strong gravitational attraction. In one way of visualizing it, it really is a bit like falling into a hole, but not like being hoovered into it. Gravity is a fundamental force of Nature, and all matter has it. When something is pulled into a black hole, the process is more like being pulled into like a fish being reeled in by an angler, rather than being pushed along like a rafter inexorably being dragged over a waterfall.

The difference may seem trivial, but from a physical standpoint it is fundamental.

So black holes don’t suck, but they are very cool. Actually, they are cold. Very, very cold. But that’s a story for another time.

Originally Published at earthsky

As a Christmas present to the world, the Comet Lovejoy became the star of the season. Not only were beautiful photos taken of it but also an amazing time-lapse video was put together of the comet rising just before the sun. The video was the project of Gabriel Brammer of the long-tailed iceball rising from the horizon. Enjoy the photos and video below of this wonderful sight to behold.

What is Lovejoy?

C/2011 W3 "Lovejoy" is a periodic comet, classified as a Kreutz Sungrazer. It was discovered on 27 November 2011, by amateur astronomer Terry Lovejoy. The comet's perihelion took it through the Sun's corona on 16 December 2011 at 00:35 UTC, as it passed approximately 140,000 kilometres (87,000 mi) above the Sun's surface. It was not expected to survive the encounter, but the Solar Dynamics Observatory (SDO), as well as other Sun-monitoring spacecraft, observed the comet emerge from the corona intact.

Before perihelion, the comet nucleus of Lovejoy was estimated to be between 100 and 200 metres (330 and 660 ft) in diameter, but after surviving perihelion it has been estimated that the nucleus was larger, as much as 500 m (1,600 ft) before the passage through the corona. At its brightest the comet had an apparent magnitude of around –4 (about as bright as the planet Venus). It is the brightest sungrazing comet ever observed by SOHO, and is the brightest comet to appear since Comet McNaught of 2007, which shone at visual magnitude –5.5. However, Lovejoy was largely invisible to the naked eye during its peak brightness as a result of its small nucleus and proximity to the Sun.

The comet first became visible to the STEREO-A spacecraft on 3 December, and to the SOHO spacecraft on 14 December. Before and after Lovejoy passed through perihelion, it was the subject of observation campaigns by eighteen instruments on six satellites: STEREO-A and -B, SOHO, SDO, Hinode and PROBA2. It again became visible to ground based telescopes on 17 December. In the Southern Hemisphere, Lovejoy was a naked eye object around 21 December.
Source: Wikipedia

There are many myths and legends about the origin of the Milky Way, the galaxy cluster of stars that makes a distinctive bright streak across the night sky.

Armenian
Ancient Armenian mythology called the Milky Way the "Straw Thief's Way". According to legend, the god Vahagn stole some straw from the Assyrian king Barsham and brought it to Armenia during a cold winter. When he fled across the heavens, he spilled some of the straw along the way.

Khoisan
The Khoisan people of the Kalahari desert in southern Africa say that long ago there were no stars and the night was pitch black. A girl, who was lonely and wanted to visit other people, threw the embers from a fire into the sky and created the Milky Way.

Cherokee
A Cherokee folktale tells of a dog who stole some cornmeal and was chased away. He ran away to the north, spilling the cornmeal along the way. The Milky Way is thus called Gili Ulisvsdanvyi "The Way the Dog Ran Away".

Eastern Asia
Peoples in Eastern Asia believed that the hazy band of stars was the "Silvery River" of Heaven (Chinese: 銀河, Korean: eunha and Japanese: ginga). In one story, the stars Altair and Vega were said to be two lovers who were allowed to meet only once a year on the seventh day of the seventh month, when a flock of magpies and crows formed a bridge over the galactic river. That day is celebrated as Qi Xi, the Seventh Night

Egyptian
In Egyptian mythology, the Milky Way was considered a pool of cow's milk. It was deified as a fertility cow-goddess by the name of Bat (later on syncretized with the goddess Hathor).

Finno-Ugric
Among the Finns, Estonians and related peoples, the Milky Way was and is called "The Pathway of the Birds" (Finnish: Linnunrata, Estonian: Linnutee). The Finns observed that the migratory birds used the galaxy as a guideline to travel south, where they believed Lintukoto (bird home) resided. In Estonian folklore it is believed that the birds are led by a white bird with the head of a maiden who chases birds of prey away.[4] Only later did scientists indeed confirm this observation; the migratory birds use the Milky Way as a guide to travel to warmer, southern lands during the winter.[citation needed] The name in the Indo-European Baltic languages has the same meaning (Lithuanian: Paukščių Takas, Latvian: Putnu Ceļš).

Greek and Roman
The Greek name for the Milky way (Γαλαξίας Galaxias) is derived from the word for milk (γάλα, gala). One legend explains how the Milky Way was created by Heracles when he was a baby.His father, Zeus, was fond of his son, who was born of the mortal woman Alcmene. He decided to let the infant Heracles suckle on his divine wife Hera's milk when she was asleep, an act which would endow the baby with godlike qualities. When Hera woke up and realized that she was breastfeeding an unknown infant, she pushed him away and the spurting milk became the Milky Way.

A story told by the Roman Hyginus in the Poeticon astronomicon (ultimately based on Greek myth) says that the milk came from the goddess Ops (Greek Rhea), the wife of Saturn (Greek Cronus). Saturn swallowed his children to ensure his position as head of the Pantheon and sky god, and so Ops conceived a plan to save her newborn son Jupiter (Greek Zeus): She wrapped a stone in infant's clothes and gave it to Saturn to swallow. Saturn asked her to nurse the child once more before he swallowed it, and the milk that spurted when she pressed her nipple against the rock eventually became the Milky Way.

Older Greek mythology associates the Milky Way with a herd of dairy cows/cattle, where each cow is a star and whose milk gives the blue glow. As such, it is intimately associated with legends concerning the constellation of Gemini, with which it is in contact. The constellation was named for the twins, Castor and Polydeuces, who sometimes raided cattle. In addition, Gemini (in combination with Canis Major, Orion, Auriga, and the deserted area now called Camelopardalis) may form the origin of the myth of the Cattle of Geryon, one of The Twelve Labours of Heracles.


Hindu
In the Hindu collection of stories called Bhagavata Purana, all the visible stars and planets moving through space are likened to a dolphin that swims through the water, and the heavens is called śiśumãra cakra, the dolphin disc. The Milky Way forms the abdomen of the dolphin and is called Akasaganga which means "The Ganges River of the Sky".

Hungarian
In Hungarian mythology, Csaba, the mythical son of Attila the Hun and ancestor of the Hungarians is supposed to ride down the Milky Way when the Székelys (ethnic Hungarians living in Romania) are threatened. Thus the Milky Way is called "The Road of the Warriors" Hungarian: Hadak Útja .

Māori
To the Māori the Milky Way is the waka (canoe) of Tama-rereti. The front and back of the canoe are Orion and Scorpius, while the Southern Cross and the Pointers are the anchor and rope. According to legend, when Tama-rereti took his canoe out onto a lake, he found himself far from home as night was falling. There were no stars at this time and in the darkness the Taniwha would attack and eat people. So Tama-rereti sailed his canoe along the river that emptied into the heavens (to cause rain) and scattered shiny pebbles from the lakeshore into the sky. The sky god, Ranginui, was pleased by this action and placed the canoe into the sky as well as a reminder of how the stars were made.


Australian Aboriginal
The Kaurna Aboriginal People of the Adelaide Plains in South Australia see the band of the Milky Way as a river in the skyworld. They called it Wodliparri (wodli = hut, house, parri = river) and believe that positioned along the river are a number of dwellings. In addition, the dark patches mark the dwelling place of a dangerous creature known as a yura; the Kaurna call these patches Yurakauwe, which literally means "monster water." Moreover, Aboriginal Groups from the Cape York region of Queensland see the band of light as termites that had been blown into the sky by the ancestral hero Burbuk Boon. Further south the band of stars that comprise the Milky Way are seen as thousands of flying foxes carrying away a dancer known as Purupriggie.

In addition, the Aranda who come from central Australia see the band of the Milky Way as a river or creek in the skyworld. This stellar river separates the two great camps of the Aranda and Luritja People. The stars to the east of this river represent the camps of the Aranda and the stars to the west represent Luritja encampments and some stars closer to the band represent a mixture of both.
Source Wikipedia

There are different opinions about the stars. Some say they are balls of light, others say they are human, but most people say they are living creatures covered with luminous fur or feathers.

One night a hunting party camping in the mountains noticed two lights like large stars moving along the top of a distant ridge. They wondered and watched until the light disappeared on the other side. The next night, and the next, they saw the lights again moving along the ridge, and after talking over the matter decided to go on the morrow and try to learn the cause.

In the morning they started out and went until they came to the ridge, where, after searching some time, they found two strange creatures about so large (making a circle with outstretched arms), with round bodies covered with fine fur or downy feathers, from which small heads stuck out like the heads of terrapins. As the breeze played upon these feathers showers of sparks flew out.

The hunters carried the strange creatures back to the camp, intending to take them home to the settlements on their return. They kept them several days and noticed that every night they would grow bright and shine like great stars, although by day they were only balls of gray fur, except when the wind stirred and made the sparks fly out.

They kept very quiet, and no one thought of their trying to escape, when, on the seventh night, they suddenly rose from the ground like balls of fire and were soon above the tops of the trees. Higher and higher they went, while the wondering hunters watched, until at last they were only two bright points of light in the dark sky, and then the hunters knew that they were stars.

The annual Leonid meteor shower is a result of the tiny bits of debris and sand particles blown off from comet Temple -Tuttle. This amazing meteor shower forms a spectacular event every year in November. Let us explore some historical and astronomical facts behind the Leonid meteor shower events.

The ancient Egyptians called meteorites the "stone of heaven." The oldest Sumerian word for iron meant "sky" and "fire." The Hittites, one of the first to use weapons from smelted terrestrial iron, called the metal "fire from heaven." The Assyrians too, extracted iron from ore and called it "fragment from heaven." In Siberian legends, the sky was a dome of sewn hides through which the gods would occasionally peer, exposing a flash of the radiance beyond.Several Native American tribes thought meteors were fragments of lunar material and called them "children of the moon."
In one Native American legend, a shooting star symbolizes a young girl, far from her native land, trying to get home. In another, it's a coyote who had climbed up to dance among the stars.

If you live near a brightly lit city, drive away from the glow of city lights and toward the constellation from which the meteors will appear to radiate.

Clic on the picture to see in full size.