HubbleSite

It's not often that astronomers stumble across a celestial interloper that they can only describe as "weird and freakish." Hubble researchers say they were "literally dumbfounded" when they took a close-up look at an object that lives in the asteroid belt but superficially looks like a comet. It has no less than six dust tails that seem to be forming sequentially. The entire structure rotates like a bicycle wheel with spokes on one side. One explanation is that the tails formed through a series of impulsive dust-ejection events. These could have been triggered when the gentle nudge of sunlight spun up the asteroid to the point where dust is falling off the surface and into space. Solar radiation stretches the dust into finger-like streamers. View the full article

Proxima Centauri lies in the constellation of Centaurus (the Centaur), just over four light-years from Earth. Although it looks bright through the eye of the Hubble Space Telescope, as you might expect from the nearest star to the solar system, Proxima Centauri is not visible to the naked eye. Its average luminosity is very low, and it is quite small compared to other stars, at only about an eighth of the mass of the Sun. These observations were taken using Hubble's Wide Field and Planetary Camera 2 (WFPC2) in 1996. Proxima Centauri is actually part of a triple star system – its two companions, Alpha Centauri A and B, lie out of frame. View the full article

NASA's Great Observatories are teaming up to look deeper into the universe than ever before. With a boost from natural "zoom lenses" found in space, they should be able to uncover galaxies that are as much as 100 times fainter than what the Hubble, Spitzer, and Chandra space telescopes can typically see. This ambitious collaborative program is called The Frontier Fields. Astronomers will spend the next three years peering at six massive clusters of galaxies. Researchers are interested not only as to what's inside the clusters, but also what's behind them. The gravitational fields of the clusters brighten and magnify distant background galaxies that are so faint they would otherwise be unobservable. Despite several deep field surveys, astronomers realized that a lot is still to be learned about the distant universe. And, such knowledge will help in planning the observing strategy for the next-generation space observatory, the James Webb Space Telescope. View the full article

A team of astronomers has discovered a galaxy that sets the current distance record for galaxies whose distance has been definitively measured by spectroscopic redshift. The galaxy is seen as it was at a time just 700 million years after the Big Bang, when the universe was only about 5 percent of its current age of 13.8 billion years. This galaxy and dozens of others were selected for follow-up observations from the approximately 100,000 galaxies discovered in the Hubble Space Telescope CANDELS survey (Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey). The team used the Keck I Telescope in Hawaii to measure the redshift of the CANDELS galaxy, designated z8_GND_5296, at 7.51. This is the highest galaxy redshift ever confirmed. The spectral redshift of galaxies is caused by the expansion of space from the Big Bang. View the full article

A new image of the sunward plunging Comet ISON taken by NASA's Hubble Space Telescope on October 9, 2013, suggests that the comet is intact despite some predictions that the fragile icy nucleus might disintegrate as the Sun warms it. The comet will pass closest to the Sun on November 28. View the full article

An international team of astronomers has found the most distant gravitational lens yet a galaxy that, as predicted by Albert Einstein's general theory of relativity, deflects and intensifies the light of an even more distant object. The discovery provides a rare opportunity to directly measure the mass of a distant galaxy. The observation also poses a mystery: lenses of this kind should be exceedingly rare. Given this and other recent finds, astronomers either have been phenomenally lucky or, more likely, they have underestimated substantially the number of small, very young galaxies in the early universe. The team is composed of Arjen van der Wel, Glenn van de Ven, Michael Maseda, and Hans-Walter Rix (Max Planck Institute for Astronomy [MPIA]), Gregory Rudnick (University of Kansas and MPIA), Andrea Grazian (INAF), Steven Finkelstein (University of Texas at Austin), David Koo and Sandra M. Faber (University of California, Santa Cruz), Henry Ferguson, Anton Koekemoer, and Norman Grogin (STScI), and Dale Kocevski (University of Kentucky). View the full article

Astronomer Dr. Jason Kalirai of the Space Telescope Science Institute (STScI) has been cited by Baltimore Magazine as one of the "top 40 under 40" up-and-comers in the Baltimore metropolitan region. The selection, which the magazine does every five years, looks at young Baltimore professionals in a diversity of fields who in the editor's opinion are an exceptional selection of people that will have an important impact on the future. The 35-year-old Kalirai was selected from several hundred potential candidates to be highlighted in the magazine's October issue. View the full article

If you go walking along the beach or take an ocean cruise, it's hard to believe that Earth is essentially a "dry" planet. Barely 0.02 percent of our home planet's mass is surface water. In fact, our oceans came along a few hundred million years after Earth formed 4.6 billion years ago. Though still debated, astronomers think that the primeval Earth was most likely irrigated when water-rich asteroids in the solar system crashed into our planet. Now astronomers have found that the same water "delivery system" could have occurred in a dying star's planetary system. Hubble Space Telescope spectroscopic observations have found forensic evidence for the same kind of water-rich asteroids that may have once brought water to Earth. Observations made with Hubble's Cosmic Origins Spectrograph (COS) allowed the team of astronomers to do a robust chemical analysis of debris falling into the white dwarf star GD 61, located 150 light-years from Earth. They didn't detect planets but the building blocks of planets. The asteroids are plummeting deep into the gravitational field of the white dwarf, presumably due to gravitational perturbations from a surviving Jupiter-sized planet in the system. This is circumstantial evidence that potentially habitable planets once existed in this star system. However, the star burned out 200 million years ago. View the full article

Astronomers may have found the densest galaxy in the nearby universe. The galaxy, known as M60-UCD1, is located near a massive elliptical galaxy NGC 4649, also called M60, about 54 million light-years from Earth. This composite image shows M60 and the region around it, where data from NASA's Chandra X-ray Observatory are pink and data from NASA's Hubble Space Telescope are red, green, and blue. The Chandra image shows hot gas and double stars containing black holes and neutron stars, and the Hubble image reveals stars in M60 and neighboring galaxies including M60-UCD1. The arrow points to M60-UCD1. Packed with an extraordinary number of stars, M60-UCD1 is an "ultra-compact dwarf galaxy." It is one of the most massive galaxies of its kind, weighing 200 million times more than our Sun, based on observations with the Keck 10-meter telescope in Hawaii. Remarkably, about half of this mass is found within a radius of only about 80 light-years. This would make the density of stars about 15,000 times greater than found in Earth's neighborhood in the Milky Way, meaning that the stars are about 25 times closer. View the full article

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, containing some of the oldest surviving stars in the universe. These stellar relics are important to study because they help reveal the story of galaxy formation in the early universe. By comparison, only 150 globular clusters orbit the Milky Way galaxy. View the full article

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. Researchers suggest that there is something bizarre about star systems within the central hub of our galaxy. They would all have to be rotating perpendicular to the interstellar clouds from which they formed. At present, the best guess is that the alignment is caused by strong magnetic fields that were present when the galactic bulge formed billions of years ago. View the full article

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

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 the jet's dynamics. The movie shows that the hot plasma is spiraling along magnetic field lines generated by the 7-billion-solar-mass black hole. These so-called extragalactic jets are seen elsewhere in the universe, but this comparatively nearby jet is offering a detailed look at what powers and aligns them. When Lick Observatory astronomer Heber Curtis first saw the jet in 1918 he described it as "a curious straight ray." Little might Curtis have imagined that we'd someday follow it blazing across space. View the full article

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 expansion of the universe the visible light detected in distant galaxies actually maps only the ultraviolet emissions of the galaxies. Because this radiation only comes from regions of active star formation the galaxies appeared to be clumpy and messy, with no resemblance to the galaxy shapes we see around us today. By observing the galaxies in infrared light with Hubble's Wide Field Camera 3, astronomers could observe how these distant galaxies would appear normally in visible light if their radiation were not stretched to infrared wavelengths by the expanding universe. View the full article

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 Magellanic Cloud. View the full article

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 the blast. The afterglow reveals for the first time a new kind of stellar blast called a kilonova, an explosion predicted to accompany a short-duration gamma-ray burst. The kilonova is the "smoking gun" evidence that short-duration bursts are sparked by the merger of two small, super-dense stellar objects, such as a pair of neutron stars or a neutron star and a black hole. View the full article

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

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' births. View the full article

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

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's extraordinary sensitivity and sharpness caught an object that is roughly one hundred million times fainter than the faintest star that can be seen with the naked eye. Thankfully, Showalter also had 150 archival Neptune photographs taken by Hubble from 2004 to 2009. The same white dot appeared over and over again. This allowed him to plot a circular orbit for the moon, designated S/2004 N 1, which completes one revolution around Neptune every 23 hours. His discovery raises the number of known moons orbiting Neptune to 14. View the full article

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

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

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

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. View the full article

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. View the full article