This year's first image: A composite image of visible-light observations by NASA's Hubble Space Telescope, combined with infrared data from the ground-based Large Binocular Telescope in Arizona to assemble a dramatic view of the well-known Ring Nebula. The Ring Nebula is the glowing remains of a Sun-like star, the smoldering core, called a white dwarf, is the tiny white dot in the center of the Nebula. The object is tilted toward Earth so that astronomers see the ring face-on. The Hubble observations reveal that the nebula's shape is more complicated than astronomers thought. The blue gas in the nebula's center is actually a football-shaped structure that pierces the red doughnut-shaped material. Hubble also uncovers the detailed structure of the dark, irregular knots of dense gas embedded along the inner rim of the ring. The faint, scallop-shaped material surrounding the ring was expelled by the star during the early stages of the planetary nebula formation. Most Sun-like stars become planetary nebulae at the end of their lives. Once a star consumes all of its hydrogen, the nuclear fuel that makes it shine, it expands to a red giant. The bloated star then expels its outer layers, exposing its hot core. Ultraviolet radiation from the core illuminates the discarded material, making it glow. The Ring Nebula is about 2,000 light-years away in the constellation Lyra. The nebula measures roughly one light-year across.
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The gravitational field surrounding this massive cluster of galaxies, Abell 68, acts as a natural lens in space to brighten and magnify the light coming from very distant background galaxies. Like a funhouse mirror, lensing creates a fantasy landscape of arc-like images and mirror images of background galaxies. The foreground cluster is 2 billion light-years away, and the lensed images come from galaxies far behind it. In this photo, the image of a spiral galaxy at upper left has been stretched and mirrored into a shape similar to that of an alien from the classic 1970s computer game Space Invaders! A second, less distorted image of the same galaxy appears to the left of the large, bright elliptical galaxy. In the upper right of the photo is another striking feature of the image that is unrelated to gravitational lensing. What appears to be purple liquid dripping from a galaxy is a phenomenon called ram-pressure stripping. The gas clouds within the galaxy are being stripped out and heated up as the galaxy passes through a region of denser intergalactic gas.
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This light-year-long knot of interstellar gas and dust resembles a massive caterpillar. Harsh winds from extremely bright stars are blasting ultraviolet radiation at this "wanna-be" star and sculpting the gas and dust into its long shape. The culprits are 65 of the hottest, brightest known stars, classified as O-type stars, located 15 light-years away from the knot, towards the right edge of the image. These stars, along with 500 less bright, but still highly luminous B-type stars make up what is called the Cygnus OB2 association. Collectively, the association is thought to have a mass more than 30,000 times that of our Sun. The caterpillar-shaped knot, called IRAS 20324+4057, is a protostar in a very early evolutionary stage. It is still in the process of collecting material from an envelope of gas surrounding it. However, that envelope is being eroded by the radiation from Cygnus OB2. Protostars in this region should eventually become young stars with final masses about one to ten times that of our Sun, but if the eroding radiation from the nearby bright stars destroys the gas envelope before the protostars finish collecting mass, their final masses may be reduced.
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This interacting galaxy duo is collectively called Arp 142. The pair contains the disturbed, star-forming spiral galaxy NGC 2936, along with its elliptical companion, NGC 2937 at left. Once part of a flat, spiral disk, the orbits of the galaxy's stars have become scrambled due to gravitational tidal interactions with the other galaxy. This warps the galaxy's orderly spiral, and interstellar gas is strewn out into giant tails like stretched taffy. Gas and dust drawn from the heart of NGC 2936 becomes compressed during the encounter, which in turn triggers star formation. These bluish knots are visible along the distorted arms that are closest to the companion elliptical. The reddish dust, once within the galaxy, has been thrown out of the galaxy's plane and into dark veins that are silhouetted against the bright starlight from what is left of the nucleus and disk. The companion elliptical, NGC 2937, is a puffball of stars with little gas or dust present. The stars contained within the galaxy are mostly old, as evidenced by their reddish color. There are no blue stars that would be evidence of recent star formation. While the orbits of this elliptical's stars may be altered by the encounter, it's not apparent that the gravitational pull by its neighboring galaxy is having much of an effect. Arp 142 lies 326 million light-years away in the southern constellation Hydra.
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The stellar nursery of the Carina Nebula. What appears to be a craggy mountaintop enshrouded by wispy clouds, is actually a three-light-year-tall pillar of gas and dust that is being eaten away by the brilliant light from nearby bright stars. The pillar, some 7,500 light-years distant, is also being assaulted from within, as infant stars buried inside it fire off jets of gas that can be seen streaming from towering peaks. Nestled inside this dense mountain are fledgling stars. Long jets of gas can be seen shooting in opposite directions off the pedestal at the top of the image. The jets are launched by swirling disks around the young stars, which allow material to slowly accrete onto the stars' surfaces.
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The beautiful, petal-like shells of galaxy PGC 6240 are captured here in intricate detail by the NASA/ESA Hubble Space Telescope, set against a sky full of distant background galaxies. PGC 6240 is an elliptical galaxy approximately 350 million light years away in the southern constellation of Hydrus, the Water Snake. It is orbited by a number of globular clusters that contain both young and old stars - thought to be a result of a galactic merger in the recent past. The background is dotted with dozens of other more distant galaxies.
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A photo illustration of the magnificent spiral galaxy M106. Astrophotographer Robert Gendler retrieved archival Hubble images of M106 to assemble a mosaic of the center of the galaxy. He then used his own and fellow astrophotographer Jay GaBany's observations of M106 to combine with the Hubble data in areas where there was less coverage, and finally, to fill in the holes and gaps where no Hubble data existed. This portrait of M106 contains only the inner structure around the halo and nucleus. Large amounts of gas from the galaxy are thought to be falling into and fueling a supermassive black hole contained in the nucleus. Also known as NGC 4258, M106 lies 23.5 million light-years away, in the constellation Canes Venatici.
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Globular cluster Messier 15 is located some 35,000 light-years away in the constellation of Pegasus (The Winged Horse). It is one of the oldest clusters known, with an age of around 12 billion years. Both very hot blue stars and cooler golden stars can be seen swarming together in the image, becoming more concentrated towards the cluster's bright center. Messier 15 is one of the densest globular clusters known, with most of its mass concentrated at its core. As well as stars, Messier 15 was the first cluster known to host a planetary nebula, and it has been found to have a rare type of black hole at its centre. This image is made up of observations from Hubble's Wide Field Camera 3 and Advanced Camera for Surveys in the ultraviolet, infrared, and optical parts of the spectrum.
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The iconic Horsehead Nebula has graced astronomy books ever since its discovery over a century ago. In this Hubble Space Telescope view, the nebula appears in a new light, as seen in infrared wavelengths. The nebula, shadowy in optical light, appears transparent and ethereal when seen in the infrared, represented here with visible shades. The rich tapestry of the Horsehead Nebula pops out against the backdrop of Milky Way stars and distant galaxies that are easily seen in infrared light. The backlit wisps along the Horsehead's upper ridge are being illuminated by Sigma Orionis, a young five-star system just off the top of the Hubble image. A harsh ultraviolet glare from one of these bright stars is slowly evaporating the nebula. Along the nebula's top ridge, two fledgling stars peek out from their now-exposed nurseries. Gas clouds surrounding the Horsehead have already dissipated, but the tip of the jutting pillar contains a slightly higher density of hydrogen and helium, laced with dust. This casts a shadow that protects material behind it from being photo-evaporated, and a pillar structure forms. Astronomers estimate that the Horsehead formation has about five million years left before it too disintegrates.
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A snapshot of MyCn18, a young planetary nebula, reveals that the object has an hourglass shape with an intricate pattern of "etchings" in its walls. A planetary nebula is the glowing relic of a dying, Sun-like star. The results are of great interest because they shed new light on the poorly understood ejection of stellar matter that accompanies the slow death of Sun-like stars.
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Galaxy group Stephan's Quintet is 290 million light-years away, in the constellation Pegasus. Four of these five galaxies are actually close enough to be locked in a vast intricate dance. Galaxy NGC 7320, the brighter galaxy at lower left, appears to be part of the group, but is in fact 250 million light years closer than the others
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