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  1. Just about anything is possible in our remarkable universe, and it often competes with the imaginings of science fiction writers and filmmakers. Hubble's latest contribution is a striking photo of what looks like a double-bladed lightsaber straight out of the Star Wars films. In the center of the image, partially obscured by a dark, Jedi-like cloak of dust, a newborn star shoots twin jets out into space as a sort of birth announcement to the universe. Gas from a surrounding disk rains down onto the dust-obscured protostar and engorges it. The material is superheated and shoots outward from the star in opposite directions along an uncluttered escape route – the star's rotation axis. Much more energetic than a science fiction lightsaber, these narrow energetic beams are blasting across space at over 100,000 miles per hour. This celestial lightsaber does not lie in a galaxy far, far away but rather inside our home galaxy, the Milky Way. View the full article
  2. Hubble has captured an image of the first-ever predicted supernova explosion. The reappearance of the supernova dubbed "Refsdal" was calculated by different mass models of a galaxy cluster whose immense gravity is warping the supernova's light as the light travels toward Earth. The supernova was previously seen in November 2014 behind the galaxy cluster MACS J1149.5+2223, part of Hubble's Frontier Fields program. Astronomers spotted four separate images of the supernova in a rare arrangement known as an Einstein Cross. This pattern was seen around a galaxy within MACS J1149.5+2223. While the light from the cluster has taken about five billion years to reach us, the supernova itself exploded much earlier, nearly 10 billion years ago. The detection of Refsdal's reappearance served as a unique opportunity for astronomers to test their models of how mass – especially that of mysterious dark matter – is distributed within this galaxy cluster. View the full article
  3. A survey of Jupiter-sized exoplanets conducted with the Hubble and Spitzer space telescopes has solved a long-standing mystery – why some of these worlds seem to have less water than expected. Astronomers have found that planets called hot Jupiters (which orbit very close to their stars) that are apparently cloud-free show strong signs of water. However, atmospheres of other planets with faint water signals also contained clouds and haze – both of which are known to hide water from view. The findings show that planetary atmospheres are much more diverse than expected. Also, the results offer insights into the wide range of planetary atmospheres in our galaxy and how planets are assembled. View the full article
  4. For the past 60 years, astronomers have been puzzled by an unusual type of star that looks hotter and bluer than it should for its age. It has been dubbed a "blue straggler" because it seems to lag behind the evolution of neighboring stars. Blue stragglers dwell inside ancient star clusters that should have stopped making youthful and short-lived blue stars billions of years ago. The most popular explanation among several competing theories is that an aging star spills material onto a smaller companion star. The small star bulks up on mass to become hotter and bluer, while the aging companion burns out and collapses to a white dwarf – a burned out cinder. To test this theory, astronomers using the Hubble Space Telescope conducted a survey of the open star cluster NGC 188 that has 21 blue stragglers. Of those they found that seven had white dwarf companions, by identifying their ultraviolet glow that is detectable by Hubble. This confirms the binary star theory for their origin. View the full article
  5. Hunting for faraway galaxies that existed long, long ago is like a fishing trip for astronomers. So far only the "big fish" have been found, bright galaxies that existed just a few hundred million years after the big bang. Now, using the Hubble and Spitzer space telescopes, astronomers have caught a "smaller fish," a very compact and faint early galaxy that was forming 400 million years after the big bang, which happened 13.8 billion years ago. As there are many smaller fish than big fish in the sea, the new finding is evidence for an underlying population of dim galaxies that must have been common in the early universe. Hubble's upcoming successor, the James Webb Space Telescope, should be able to survey this population. But for now, Hubble can do some pioneering work by exploiting a "zoom lens" in space that captures a galaxy that would otherwise not be detectible. The phenomenon is called gravitational lensing, where the intense gravity of a cluster of galaxies magnifies the light of fainter background sources. Astronomers needed the infrared sensitivity of both the Hubble and Spitzer telescopes to measure the galaxy's great distance through its color, which is affected by the expanding universe. View the full article
  6. About 13 billion years ago, long before our sun formed, the construction of our Milky Way galaxy was just beginning. Young, mostly sun-like stars in the core, or central bulge, provided the building blocks for the galaxy's foundation. Many of these building-block stars have long since burned out, and are now just dying embers. But contained within these dead stars, called white dwarfs, is the early history of our galaxy, providing clues on how it came to be. Finding these stellar relics, however, is a daunting task. Astronomers have had a difficult time picking out these dim objects from among the crowd of bright stars that fill the space between us and the core. Using Hubble Space Telescope images, astronomers have now conducted a "cosmic archaeological dig" of our Milky Way's heart, uncovering the blueprints of our galaxy's early construction phase. Hubble researchers have uncovered for the first time a population of ancient white dwarfs. The Hubble analysis represents the deepest, most detailed study of our galaxy's central bulge of stars. View the full article
  7. Dr. Kenneth R. Sembach has been appointed director of the Space Telescope Science Institute (STScI) in Baltimore. STScI is operated by the Association of Universities for Research in Astronomy (AURA) under contract with NASA to conduct the science program of the Hubble Space Telescope and to develop the Science and Mission Operations Center for the James Webb Space Telescope. The Institute also operates the Barbara A. Mikulski Archive for Space Telescopes for NASA. Sembach succeeds Dr. Matt Mountain, who had served as STScI director since 2005. View the full article
  8. A team of astronomers is proposing that huge spiral patterns seen around some newborn stars, merely a few million years old (about one percent our sun's age), may be evidence for the presence of giant, unseen planets. This idea not only opens the door to a new method of planet detection, but also could offer a look into the early formative years of planet birth. Though astronomers have cataloged thousands of planets orbiting other stars, the very earliest stages of planet formation are elusive because nascent planets are born and embedded inside vast, pancake-shaped disks of dust and gas encircling newborn stars. The conclusion that planets may betray their presence by modifying circumstellar disks on large scales is based on detailed computer modeling of how gas-and-dust disks evolve around newborn stars. View the full article
  9. Astronomers are conducting extensive observations to estimate how many planets in our Milky Way galaxy might be potential abodes for life. These are collectively called "Earth-like" – in other words, Earth-sized worlds that are at the right distances from their stars for moderate temperatures to nurture the origin of life. The search for extraterrestrial intelligent life in the universe (SETI) is based on the hypothesis that some fraction of worlds, where life originates, go on to evolve intelligent technological civilizations. Until we ever find such evidence, Earth is the only known abode of life in the universe. But the universe is not only vastly big, it has a vast future. There is so much leftover gas from galaxy evolution available that the universe will keep cooking up stars and planets for a very long time to come. In fact, most of the potentially habitable Earth-like planets have yet to be born. This theoretical conclusion is based on an assessment of star-birth data collected by the Hubble Space Telescope and exoplanet surveys made by the planet-hunting Kepler space observatory. View the full article
  10. Scientists using NASA's Hubble Space Telescope have produced new global maps of Jupiter – the first in a series of annual portraits of the solar system's outer planets from the Outer Planet Atmospheres Legacy program (OPAL). The two Jupiter maps, representing nearly back-to-back rotations of the planet on Jan. 19, 2015, show the movements of the clouds and make it possible to determine the speeds of Jupiter's winds. The Hubble observations confirm that the Great Red Spot continues to shrink and become more circular. In addition, an unusual wispy filament is seen, spanning almost the entire width of the vortex. These findings are described in a new paper published online in the October 10 issue of The Astrophysical Journal. The collection of maps to be obtained over time from the OPAL program will not only help scientists understand the atmospheres of our giant planets, but also the atmospheres of planets being discovered around other stars. View the full article
  11. Though astronomers have discovered thousands of planets orbiting other stars, very little is known about how they are born. The conventional wisdom is that planets coagulate inside a vast disk of gas and dust encircling newborn stars. But the details of the process are not well understood because it takes millions of years to happen as the disk undergoes numerous changes until it finally dissipates. The young, nearby star AU Microscopii (AU Mic) is an ideal candidate to get a snapshot of planet birthing because the disk is tilted nearly edge on to our view from Earth. This very oblique perspective offers an opportunity to see structure in the disk that otherwise might go unnoticed. Astronomers are surprised to uncover fast-moving, wave-like features embedded in the disk that are unlike anything ever observed, or even predicted. Whatever they are, these ripples are moving at 22,000 miles per hour – fast enough to escape the star's gravitational pull. This parade of blob-like features stretches farther from the star than Pluto is from our sun. They are so mysterious it's not known if they are somehow associated with planet formation, or some unimagined, bizarre activity inside the disk. View the full article
  12. Not long before the dawn of recorded human history, our distant ancestors would have witnessed what appeared to be a bright new star briefly blazing in the northern sky, rivaling the glow of our moon. In fact, it was the titanic detonation of a bloated star much more massive than our sun. Now, thousands of years later, the expanding remnant of that blast can be seen as the Cygnus Loop, a donut-shaped nebula that is six times the apparent diameter of the full moon. The Hubble Space Telescope was used to zoom into a small portion of that remnant, called the Veil Nebula. Hubble resolves tangled rope-like filaments of glowing gases. Supernovae enrich space with heavier elements used in the formation of future stars and planets – and possibly life. View the full article
  13. Astronomers have discovered a rare beast of a galaxy cluster whose heart is bursting with new stars. The unexpected find, made with the help of NASA's Spitzer and Hubble space telescopes, suggests that behemoth galaxies at the cores of these massive clusters can grow significantly by feeding on gas stolen from other galaxies. The cluster in the new study, referred to by astronomers as SpARCS1049+56, has at least 27 galaxy members, and a combined mass equal to nearly 400 trillion suns. It is located 9.8 billion light-years away in the Ursa Major constellation. The object was initially discovered using Spitzer and the Canada-France-Hawaii Telescope, and confirmed using the W. M. Keck Observatory. Hubble helped confirm the source of the fuel for the new stars. View the full article
  14. Astronomers at the University of California at Irvine (UCI) and the Space Telescope Science Institute have made the most accurate statistical estimate of the number of faint, small galaxies that existed only 500 million years after the big bang. This was culled from an analysis of the deepest Hubble Space Telescope sky survey, CANDELS (Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey). Previously, studies using Caltech's CIBER (the Cosmic Infrared Background Experiment) rocket-borne instrument and NASA's Spitzer Space Telescope images confirmed the presence of "intra-halo light" from stars distributed outside of galaxies. The Hubble data found a new component in the infrared background in addition to intra-halo light – the collective glow of entire galaxies that formed first in the universe. UCI's Asantha Cooray believes that these early galaxies are very different from the well-defined spiral and disk-shaped galaxies seen in the present-day universe. They were more diffuse and populated by giant stars. This discovery paves the way for NASA's James Webb Space Telescope to see these very faint galaxies individually, after its launch in 2018. View the full article
  15. All stars are not created equal. They can vary in mass by over a factor of 1,000. Our sun is classified as a diminutive yellow dwarf. What's more, stars are not born in isolation, but inside giant molecular clouds of hydrogen. The question has been: what fraction of stars precipitate out of these clouds into clusters that contain blue giants, yellow dwarfs, and red dwarfs? It's like asking if all automobile manufacturers fabricate the same proportion of trucks, SUVs, sedans, and subcompacts. The best way to address the question is not to look around our Milky Way – which we are inside – but far out into space to the neighboring Andromeda galaxy, 2.5 million light-years away. Embedded in a sweeping Hubble Space Telescope mosaic of 117 million stars in the galaxy's disk are 2,753 star clusters. Hubble astronomers found that, for whatever reason, nature apparently cooks up stars like batches of cookies. There is a consistent distribution from massive stars to small stars. It is surprising to find that this ratio is the same across our neighboring galaxy (as well as inside our stellar neighborhood in the Milky Way), given the complex physics of star formation. View the full article
  16. Quasars are the light fantastic. These brilliant cores of active galaxies blaze with the radiance of a hundred billion stars compressed into a region of space not much larger than our solar system. Supermassive black holes, with millions or billions of times the mass of our sun, are the only imaginable powerhouse behind these tsunamis of raw energy. Hubble Space Telescope astronomers set their sights on the nearest quasar to Earth, Markarian 231, located 581 million light-years away. Black holes – even supermassive ones – are too compact to be resolved by any present-day telescope. So, astronomers did the next best thing, measure all the light from a disk of infalling material around the black hole. The ultraviolet radiation – only measurable by Hubble – revealed evidence for a curious gap in the disk. Instead of being pancake shaped, it looks more like it has a big donut hole. The best explanation for the gap is that two black holes are orbiting each other in a dizzying dance that powers the quasar fireworks. This carves out the gap. The second black hole must have come from a smaller galaxy that merged with Markarian 231 to ignite the quasar about 1 million years ago. View the full article
  17. A team of astronomers, including half a dozen from the Space Telescope Science Institute (STScI) in Baltimore, Maryland, have used the Gemini Observatory's new Gemini Planet Imager to find the most solar system-like planet ever directly imaged around another star. The planet, known as 51 Eridani b, is about two times the mass of Jupiter and orbits its host star at about 13 times the Earth-sun distance (equivalent to being between Saturn and Uranus in our solar system). The planet is located about 100 light-years away from Earth. The Gemini data provide scientists with the strongest-ever spectroscopic detection of methane in the atmosphere of an extrasolar planet, adding to its similarities to giant planets in our solar system. "This planet looks like a younger, slightly bigger version of Jupiter," said Dr. Laurent Pueyo of STScI, one of the astronomers who carefully measured the planet's light against the background glare of starlight. "That we can see so clearly the presence of methane for a planet a million times fainter than its star, even through the atmosphere, bodes very well for the future characterization of even fainter planets from space using the James Webb Space Telescope and the Wide-Field Infrared Survey Telescope." View the full article
  18. What happens when you find something in the wrong place at the wrong time? That's a question astronomers have been trying to answer after finding several exploding stars outside the cozy confines of galaxies, where most stars reside. These wayward supernovae also have puzzled astronomers because they exploded billions of years before their predicted detonations. Astronomers using archived observations from several telescopes, including the Hubble Space Telescope, have developed a theory for where these doomed stars come from and how they arrived at their current homes. According to their scenario, the supernovae were once stars in double-star systems that wandered too close to twin supermassive black holes at the core of a merging galaxy. The black-hole duo gravitationally catapulted the stars out of their home galaxies. The interaction pulled the stars closer together, which accelerated the merger between each pair. Eventually, the stars moved close enough to trigger a supernova blast. View the full article
  19. Astronomers have long wondered how the universe's largest elliptical galaxies continue making stars long after their peak years of star birth. By combining data from NASA's Hubble Space Telescope with observations from a suite of ground-based and space telescopes, two independent teams have uncovered a unique process to explain how this star birth continues. The teams found that that the galaxy's central black hole, jets, and newborn stars are all parts of a self-regulating cycle. In that cycle, jets shooting out of the galaxy's center heat a halo of surrounding gas, controlling the rate at which it cools and falls into the galaxy. The astronomers used Hubble's high resolution and ultraviolet vision to resolve brilliant knots of hot, blue stars forming along the jets from active black holes in the centers of these giant galaxies. View the full article
  20. The majority of planets discovered outside our solar system orbit close to their parent stars because these planets are the easiest to find. But to fully understand how distant planetary systems are put together, astronomers must conduct a census of all the planets around a star. So they need to look farther away from the star-from about the distance of Jupiter is from our sun, and beyond. Now, astronomers using NASA's Hubble Space Telescope and the W. M. Keck Observatory in Hawaii have confirmed the existence of a Uranus-sized exoplanet orbiting far from its central star, discovered through a technique called gravitational microlensing. Microlensing occurs when a foreground star magnifies the light of a background star that momentarily aligns with it. The unique signature of the event, which is influenced by the relative motion of the stars across space, can reveal clues to the nature of the foreground star and any associated planets. Gravitational microlensing can find cold planets in long-period orbits that other methods cannot detect. This finding opens a new piece of discovery space in the extrasolar planet hunt: to uncover planets as far from their central stars as Jupiter and Saturn are from our sun. View the full article
  21. Astronomers using NASA's Hubble Space Telescope have discovered an immense cloud of hydrogen dubbed "The Behemoth" bleeding off a planet orbiting a nearby star. The enormous, comet-like feature is about 50 times the size of the parent star. The hydrogen is evaporating from a warm, Neptune-sized planet, due to extreme radiation from the star. A phenomenon this large has never before been seen around any exoplanet. It may offer clues to how Super-Earths – massive, rocky, versions of Earth – are born around other stars through the evaporation of their outer layers of hydrogen. Finding "The Behemoth" could be a game-changer for characterizing atmospheres of the whole population of Neptune-sized planets and Super-Earths in ultraviolet observations. View the full article
  22. Quasars are the light fantastic. They are the brightest beacons in the universe, blazing across space with the intrinsic brightness of one trillion suns. Yet the objects are not vast galaxies, but they appear as pinpoint sources in the biggest telescopes of today – hence the term "quasar" for quasi-stellar object. Discovered in the 1960s, it took more than two decades of research to come to the conclusion that quasars are produced by the gusher of energy coming from over-fed supermassive black holes inside the cores of very distant galaxies. And, most quasars bloomed into a brief existence 12 billion years ago. The big question has been, why? What was happening in the universe 12 billion years ago? The universe was smaller and so crowded that galaxies collided with each other much more frequently than today. Astronomers using Hubble's near-infrared vision tested this hypothesis by looking at dusty quasars where their glow was suppressed by dust, allowing a view of the quasar's surroundings. Hubble's sharp vision revealed chaotic collisions between galaxies that gave birth to quasars by fueling a supermassive central black hole. View the full article
  23. Researchers using NASA's Hubble Space Telescope have detected a stratosphere and temperature inversion in the atmosphere of a planet several times the mass of Jupiter, called WASP-33b. Earth's stratosphere sits above the troposphere, the turbulent, active-weather region that reaches from the ground to the altitude where nearly all clouds top out. In the troposphere, the temperature is warmer at the bottom – ground level – and cools down at higher altitudes. The stratosphere is just the opposite: There, the temperature rises at higher altitudes. This is called a temperature inversion, and it happens because ozone in the stratosphere absorbs some of the sun's radiation, preventing it from reaching the surface and warming this layer of the atmosphere. Similar temperature inversions occur in the stratospheres of other planets in our solar system, such as Jupiter and Saturn. But WASP-33b is so close to its star that its atmosphere is a scathing 10,000 degrees Fahrenheit, and its atmosphere is so hot the planet might actually have titanium oxide rain. View the full article
  24. This magnificent spiral galaxy is at the edge of what astronomers call the Local Void. The Local Void is a huge volume of space that is at least 150 million light-years across that doesn't seen to contain anything much. There are no obvious galaxies. This void is simply part of the structure of the universe where matter grows clumpy over time so that galaxies form clusters and chains, which are separated by regions mostly devoid of galaxies. This results in sort of a "soap bubble" structure on large scales. The galaxy, as photographed by NASA's Hubble Space Telescope, is especially colorful where bright red patches of gas can be seen scattered through its spiral arms. Bright blue regions contain newly forming stars. Dark brown dust lanes snake across the galaxy's bright arms and center, giving it a mottled appearance. View the full article
  25. Two of the most reliable changes in the sky are the daily rising of the sun in the east and setting of the sun in the west. But if you lived on a couple of Pluto's moons you wouldn't know when the day would begin, or even what direction the sun would rise. That's because, unlike Earth's moon, at least two of Pluto's small moons, Hydra and Nix, are tumbling chaotically through space. Why? Because they orbit inside a dynamically shifting gravitational field caused by the system's two central bodies, Pluto and Charon, that are whirling around each other. The moons are also football shaped, and this contributes to the chaotic rotation. By contrast, Earth's moon keeps the same face toward us, because the gravitational forces between Earth and the moon cause the moon to dynamically settle into a condition called tidal lock, where it keeps one hemisphere facing Earth. Almost all of the solar system's major moons also behave similarly. But the Pluto moons essentially orbit a "double planet." And this makes life complicated. Over the past several years, the Hubble Space Telescope has discovered four tiny satellites orbiting Pluto and Charon. Researchers were puzzled by unpredictable changes in the sunlight reflected off the two brighter moons. They finally concluded that at least two of the moons must be tumbling unpredictably. View the full article
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