Astronomy and Stars
Discussions about astronomy and stars. As we look further out what can we find in the universe beyond Earth's atmosphere?
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Ten years ago, astronomer John Blakeslee spotted dots of light peppered throughout images of a giant cluster of galaxies, called Abell 1689. Each dot was not one star, but hundreds of thousands of stars crowded together in groupings called globular clusters. Blakeslee counted 500 such clusters, the brightest members of a teeming population of globular clusters. Now, a new Hubble census of globular clusters in Abell 1689 reveals that an estimated 160,000 such groupings are huddled near the galaxy cluster's core. The Hubble observations break the record for the farthest and the most globular clusters ever seen. Globular clusters are the homesteaders of galaxies, containin…
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Hubble astronomers have found an unexpected surprise while surveying more than 100 planetary nebulae in the central bulge of our Milky Way galaxy. Those nebulae that are butterfly-shaped or hourglass-shaped tend to be mysteriously aligned such that their rotation axis is perpendicular to the plane of our galaxy. Planetary nebulae are the expanding gaseous shrouds encircling dying stars. A subset of this population has bipolar outflows that align to the star's rotation axis. Such nebulae formed in different places and have different characteristics and so it is a puzzle why they should always point on the same sky direction, like bowling pins set up in an alley. Resear…
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This light-year-long knot of interstellar gas and dust resembles a caterpillar on its way to a feast. But the meat of the story is not only what this cosmic caterpillar eats for lunch, but also what's eating it. 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. View the full article
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The universe is so big, and it takes so long for most celestial objects to change, that it is rare a telescope can catch something in motion. It helps if the target is moving at nearly the speed of light, and that the Hubble Space Telescope's crystal-clear view can catch subtle changes in one-tenth the time it might take for a ground-based telescope. Astronomers collected 500 Hubble pictures, taken over 13 years to make a movie flipbook of a blowtorch-like jet of gas blasted from the vicinity of a supermassive black hole. The black hole resides in the center of the galaxy M87. The jet has been known about for nearly a century. But the new Hubble movie provides a look at t…
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Looking 11 billion years back in time to when the universe was very young, astronomers have found that the anatomy of distant galaxies is not that different from galaxies seen in the nearby universe today. The results come from the Hubble Space Telescope Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS). The largest project in the history of Hubble, it aims to explore galactic evolution in the early universe, and the very first seeds of cosmic structure at less than 1 billion years after the Big Bang. Previous studies of this early epoch were inconclusive because they were limited to visible light. Because of the stretching of light by the expansi…
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Astronomers using NASA's Hubble Space Telescope have solved a 40-year mystery on the origin of the Magellanic Stream, a long ribbon of gas stretching nearly halfway around our Milky Way galaxy. The Large and Small Magellanic Clouds, two dwarf galaxies orbiting the Milky Way, are at the head of the gaseous stream. Since the stream's discovery by radio telescopes in the early 1970s, astronomers have wondered whether the gas comes from one or both of the satellite galaxies. Now, new Hubble observations reveal that most of the gas was stripped from the Small Magellanic Cloud about 2 billion years ago, and a second region of the stream originated more recently from the Large…
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Ever since U.S. Air Force satellites serendipitously discovered gamma-ray bursts in the 1960s, astronomers have been searching for the triggering mechanism. Gamma-ray bursts are mysterious flashes of intense high-energy radiation that appear from random directions in space. These titanic explosions unleash as much energy in less than a second as the Sun does in 1 million years. Now, astronomers are using NASA's Hubble Space Telescope to gather key evidence on what powers short-duration gamma-ray bursts, which last up to two seconds. Probing the location of a recent short-duration burst in near-infrared light, Hubble found the fading fireball produced in the aftermath of…
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In this Hubble Space Telescope composite image taken in April 2013, the sun-approaching Comet ISON floats against a seemingly infinite backdrop of numerous galaxies and a handful of foreground stars. The icy visitor, with its long gossamer tail, appears to be swimming like a tadpole through a deep pond of celestial wonders. This photo is one of the original images featured on ISONblog, a new online source offering unique analysis of Comet ISON by Hubble Space Telescope astronomers and staff at the Space Telescope Science Institute in Baltimore, Md. View the full article
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Billions of years ago in our Milky Way galaxy, long before the Earth was born, swarms of stars formed in giant clusters. Each grouping of stars, called a globular cluster, was held together by the mutual gravity of its stars. These globular star clusters became the homesteaders of our Milky Way. Astronomers have probed the galaxy's globular clusters using many telescopes, including NASA's Hubble Space Telescope, to dig into the Milky Way's past and uncover what was happening in these early, formative years. Recent stellar archaeological excavations with Hubble into one such globular cluster, 47 Tucanae, have allowed astronomers to piece together a timeline of the stars'…
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Holland Ford, an astronomer at The Johns Hopkins University in Baltimore, Md., has received NASA's Distinguished Public Service Medal for his outstanding contributions to the Hubble Space Telescope. The Distinguished Public Service Medal is NASA's highest form of recognition, awarded to someone who has made a profound impact on the success of a NASA mission. The medal is one of several NASA Agency Honor Awards given annually. View the full article
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In the summer of 1989, a robotic emissary from Earth visited the farthest major planet from the Sun, Neptune. Like any good tourist, NASA's Voyager 2 spacecraft snapped a lot of pictures during the brief flyby. The prolific probe discovered several moons orbiting close to the blue-green planet. But one moon, no bigger than a metropolitan city and nearly coal-black, escaped detection because it was too faint to be seen. Until now. While analyzing Neptune photos taken by the Hubble Space Telescope, astronomer Mark Showalter of the SETI Institute noticed an extra white dot about 65,400 miles from Neptune, located between the orbits of the moons Larissa and Proteus. Hubble'…
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Hubble has identified the true visible-light color of a giant Jupiter-sized planet located 63 light-years away. The planet has a cobalt blue color. It has torrential 4,500-mile-per-hour winds that are so hot they melt silicates into raindrops of molten glass. And that's where the cobalt-blue hue comes from, not oceans. The glass droplets scatter blue light more readily than green or red light. The planet's color provides unique clues to the atmosphere and weather on a truly alien world that orbits much closer to its star than the innermost planet Mercury is to our Sun. View the full article
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This July 4th, the solar system is showing off some fireworks of its own. Superficially resembling a skyrocket, Comet ISON is hurtling toward the Sun at a whopping 48,000 miles per hour. Unlike a firework, the comet is not combusting, but in fact is pretty cold. Its skyrocket-looking tail is really a streamer of gas and dust bleeding off the icy nucleus. The video shows a sequence of Hubble observations taken over a 43-minute span, compressed into just five seconds. The comet travels 34,000 miles during the exposure sequence. View the full article
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What looks like a celestial hummingbird is really the result of a collision between a spiral and an elliptical galaxy at a whopping 326 million light- years away. The flat disk of the spiral NGC 2936 is warped into the profile of a bird by the gravitational tug of the companion NGC 2937. The object was first cataloged as a "peculiar galaxy" by Halton Arp in the 1960s. This interacting galaxy duo is collectively called Arp 142. View the full article
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Nearly 900 extrasolar planets have been confirmed to date, but now for the first time astronomers think they are seeing compelling evidence for a planet under construction in an unlikely place, at a great distance from its diminutive red dwarf star. The keen vision of NASA's Hubble Space Telescope has detected a mysterious gap in a vast protoplanetary disk of gas and dust swirling around the nearby star TW Hydrae, located 176 light-years away in the constellation Hydra (the Sea Serpent). The gap's presence is best explained as due to the effects of a growing, unseen planet that is gravitationally sweeping up material and carving out a lane in the disk, like a snow plow.…
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After 45 years of peaceful bliss, the nova T Pyxidis erupted again in 2011. Astronomers took advantage of a flash of light accompanying the blast to map the ejecta from previous outbursts surrounding the double-star system. The team used NASA's Hubble Space Telescope to trace the light as it sequentially illuminated different parts of the disk, a phenomenon called a light echo. Contrary to some predictions, the astronomers were somewhat surprised to find that the ejecta stayed in the vicinity of the star and formed a disk of debris. The discovery suggests that material continues expanding outward along the system's orbital plane, but it does not escape the system. …
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The ancients thought that stars were fixed pinpoints of light on the sky. Today we know that they are all moving, like fish in a pond. This so-called proper motion is so small that it is not noticeable to the human eye over a single lifetime. But Hubble can precisely track stellar motions to razor-sharp precision. Not surprisingly the nearest star to our Sun, Proxima Centauri, is one of the fastest moving across the sky. Hubble astronomers have found that it will pass in front of two far-more distant background stars, once in 2014 and again in 2016. This will afford a very rare opportunity to see how Proxima's gravity warps the image of the background stars by bending the…
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The distinctive shape of the Ring Nebula, the glowing shroud around a dying Sun-like star, makes it a popular celestial object that appears in many astronomy books. New observations of the Ring Nebula by NASA's Hubble Space Telescope, however, reveal a new twist on an iconic nebula. The Hubble images offer the best view yet of the nebula, revealing a complex structure. The observations have allowed astronomers to construct the most precise three-dimensional model of the glowing gas shroud, called a planetary nebula. Based on the new observations, the Hubble research team suggests that the ring wraps around a blue football-shaped structure that protrudes out of opposite …
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Deep inside the Hyades star cluster, a pair of burned-out stars are yielding clues to the presence of rocky planets that may have whirled around them. Asteroid debris is 'raining' into the hot atmospheres of these white dwarfs. Asteroids should consist of the same material that form terrestrial planets, and seeing evidence of asteroids points to the possibility of Earth-sized planets in the same system. Hubble's Cosmic Origins Spectrograph observed silicon and only low levels of carbon in the white dwarfs' atmospheres. Silicon is a major ingredient of the rocky material that constitutes Earth and other solid planets in our solar system. Astronomers used sophisticated co…
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The Space Telescope Science Institute has appointed Dr. Massimo Stiavelli as the James Webb Space Telescope (JWST) Mission Head. Stiavelli will be responsible for the development and operations of the JWST Science and Operations Center at STScI. He has been acting JWST Mission Head since January 2012. The largest space observatory ever developed, JWST is scheduled for launch in 2018. Stiavelli succeeds Dr. Kathy Flanagan, who was appointed the Institute's Deputy Director in October 2012. Stiavelli has worked at the Institute for over 17 years. His many positions at the Institute include instrument scientist for three Hubble cameras. Stiavelli has been working on the JWST …
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Comet ISON is potentially the "comet of the century" because around the time the comet makes its closest approach to the Sun, on November 28, it may briefly become brighter than the full Moon. Right now the comet is far below naked-eye visibility, and so Hubble was used to snap the view of the approaching comet, which is presently hurtling toward the Sun at approximately 47,000 miles per hour. When the Hubble picture was taken on April 10, the comet was slightly closer than Jupiter's orbit at a distance of 386 million miles from the Sun. Even at that great distance the Sun is warming the comet enough to trigger outgassing from its frozen gases locked up in the solid nucle…
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Unlike other celestial objects there is no question how the Horsehead Nebula got its name. This iconic silhouette of a horse's head and neck pokes up mysteriously from what look like whitecaps of interstellar foam. The nebula has graced astronomy books ever since its discovery over a century ago. But Hubble's infrared vision shows the horse in a new light. The nebula, shadowy in optical light, appears transparent and ethereal when seen at infrared wavelengths. This pillar of tenuous hydrogen gas laced with dust is resisting being eroded away by the radiation from a nearby star. The nebula is a small part of a vast star-forming complex in the constellation Orion. The Horse…
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NASA and the Space Telescope Science Institute (STScI) have announced the selection of 17 new Hubble Fellows. The Hubble Fellowship Program now includes all research relevant to present and future missions in NASA's Cosmic Origins theme. These missions currently include the Herschel Space Observatory, the Hubble Space Telescope (HST), the James Webb Space Telescope (JWST), the Stratospheric Observatory for Infrared Astronomy (SOFIA), and the Spitzer Space Telescope. STScI in Baltimore, Md., administers the Hubble Fellowship Program for NASA. More than 310 of the most prominent and active scientists in this field have been supported at a crucial phase in their careers by…
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A long time ago, in a galaxy far, far away, a star detonated with enough energy to briefly shine with an intrinsic brightness of one billion of our suns. The beacon of radiation arrived at Earth 10 billion years later and was captured in a Hubble Space Telescope deep survey of the universe. It is the farthest, and earliest, supernova of its type detected to date. More than simply an example of the ancient fireworks in the young and effervescent universe, the supernova belongs to a special class of stellar detonations that are so reliably bright, they can be used as intergalactic milepost markers. Supernovae like this one provided the first observational evidence that th…
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NASA's Chandra X-ray telescope has made the first detection of X-ray emission from young solar-type stars that lie outside our Milky Way galaxy. They live in a region known as the "Wing" of the Small Magellanic Cloud, a satellite galaxy of our Milky Way. X-rays from young stars trace how active their magnetic fields are. Magnetic activity provides clues to a star's rotation rate and the rising and falling of hot gas in the star's interior. Astronomers suggest that if the X-ray properties of young stars are similar in different environments around our galaxy, then other related properties, such as the formation of planets, are also likely to be similar. In this composite…
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