HubbleSite

Much of the light in the universe comes from stars, and yet, star formation is still a vexing question in astronomy. To piece together a more complete picture of star birth, astronomers have used the Hubble Space Telescope to look at star formation among galaxies in our own cosmic back yard. The survey of 50 galaxies in the local universe, called the Legacy ExtraGalactic UV Survey (LEGUS), is the sharpest, most comprehensive ultraviolet-light look at nearby star-forming galaxies. The LEGUS survey combines new Hubble observations with archival Hubble images for star-forming spiral and dwarf galaxies, offering a valuable resource for understanding the complexities of star formation and galaxy evolution. Astronomers are releasing the star catalogs for each of the LEGUS galaxies and cluster catalogs for 30 of the galaxies, as well as images of the galaxies themselves. The catalogs provide detailed information on young, massive stars and star clusters, and how their environment affects their development. The local universe, stretching across the gulf of space between us and the great Virgo cluster of galaxies, is ideal for study because astronomers can amass a big enough sample of galaxies, and yet, the galaxies are close enough to Earth that Hubble can resolve individual stars. The survey will also help astronomers understand galaxies in the distant universe, where rapid star formation took place. View the full article

There may be no shortage of balloon-filled birthday parties or people with silly high-pitched voices on the planet WASP-107b. That's because NASA's Hubble Space Telescope was used to detect helium in the atmosphere for the first time ever on a world outside of our solar system. The discovery demonstrates the ability to use infrared spectra to study exoplanet atmospheres. Though as far back as 2000 helium was predicted to be one of the most readily-detectable gases on giant exoplanets, until now helium had not been found — despite searches for it. Helium was first discovered on the Sun, and is the second-most common element in the universe after hydrogen. It's one of the main constituents of the planets Jupiter and Saturn. An international team of astronomers led by Jessica Spake of the University of Exeter, UK, used Hubble's Wide Field Camera 3 to discover helium. The atmosphere of WASP-107b must stretch tens of thousands of miles out into space. This is the first time that such an extended atmosphere has been discovered at infrared wavelengths. View the full article

In the fading afterglow of a supernova explosion, astronomers using NASA’s Hubble Space Telescope have photographed the first image of a surviving companion to a supernova. This is the most compelling evidence that some supernovas originate in double-star systems. The companion to supernova 2001ig’s progenitor star was no innocent bystander to the explosion—it siphoned off almost all of the hydrogen from the doomed star’s stellar envelope. SN 2001ig is categorized as a Type IIb stripped-envelope supernova, which is a relatively rare type of supernova in which most, but not all, of the hydrogen is gone prior to the explosion. Perhaps as many as half of all stripped-envelope supernovas have companions—the other half lose their outer envelopes via stellar winds. View the full article

For 28 years, NASA’s Hubble Space Telescope has been delivering breathtaking views of the universe. Although the telescope has made more than 1.5 million observations of over 40,000 space objects, it is still uncovering stunning celestial gems. The latest offering is this image of the Lagoon Nebula to celebrate the telescope’s anniversary. Hubble shows this vast stellar nursery in stunning unprecedented detail. At the center of the photo, a monster young star 200,000 times brighter than our Sun is blasting powerful ultraviolet radiation and hurricane-like stellar winds, carving out a fantasy landscape of ridges, cavities, and mountains of gas and dust. This region epitomizes a typical, raucous stellar nursery full of birth and destruction. View the full article

When you want to know the size of a room, you use a measuring tape to calculate its dimensions. But you can’t use a tape measure to cover the inconceivably vast distances in space. And, until now, astronomers did not have an equally precise method to accurately measure distances to some of the oldest objects in our universe – ancient swarms of stars outside the disk of our galaxy called globular clusters. Estimated distances to our Milky Way galaxy’s globular clusters were achieved by comparing the brightness and colors of stars to theoretical models and observations of local stars. But the accuracy of these estimates varies, with uncertainties hovering between 10 percent and 20 percent. Using NASA’s Hubble Space Telescope, astronomers were able to use the same sort of trigonometry that surveyors use to precisely measure the distance to NGC 6397, one of the closest globular clusters to Earth. The only difference is that the angles measured in Hubble’s camera are infinitesimal by earthly surveyors’ standards. The new measurement sets the cluster’s distance at 7,800 light-years away, with just a 3 percent margin of error, and provides an independent estimate for the age of the universe. The Hubble astronomers calculated NGC 6397 is 13.4 billion years old and so formed not long after the big bang. The new measurement also will help astronomers improve models of stellar evolution. View the full article

NASA has selected 24 new Fellows for its prestigious NASA Hubble Fellowship Program (NHFP). The program enables outstanding postdoctoral scientists to pursue independent research in any area of NASA Astrophysics, using theory, observation, experimentation, or instrument development. Each fellowship provides the awardee up to three years of support. View the full article

Through a quirk of nature called “gravitational lensing,” a natural lens in space amplified a very distant star’s light. Astronomers using Hubble took advantage of this phenomenon to pinpoint the faraway star and set a new distance record for the farthest individual star ever seen. They also used the distant star to test one theory of dark matter, and to probe the make-up of a galaxy cluster. The team dubbed the star “Icarus,” after the Greek mythological character who flew too near the Sun on wings of feathers and wax that melted. Its official name is MACS J1149+2223 Lensed Star 1. View the full article

Grand, majestic spiral galaxies like our Milky Way are hard to miss. Astronomers can spot these vast complexes because of their large, glowing centers and their signature winding arms of gas and dust, where thousands of glowing stars reside. But some galaxies aren't so distinctive. They are big, but they have so few stars for their size that they appear very faint and diffuse. In fact, they are so diffuse that they look like giant cotton balls. Observations by NASA's Hubble Space Telescope of one such galaxy have turned up an oddity that sets it apart from most other galaxies, even the diffuse-looking ones. It contains little, if any, dark matter, the underlying scaffolding upon which galaxies are built. Dark matter is an invisible substance that makes up the bulk of our universe and the invisible glue that holds visible matter in galaxies — stars and gas — together. Called NGC 1052-DF2, this "ghostly" galaxy contains at most 1/400th the amount of dark matter that astronomers had expected. How it formed is a complete mystery. The galactic oddball is as large as our Milky Way, but the galaxy had escaped attention because it contains only 1/200th the number of stars as our galaxy. Based on the colors of its globular clusters, NGC 1052-DF2 is about 10 billion years old. It resides about 65 million light-years away. View the full article

The universe is so huge that it's estimated that a star explodes as a supernova once every second. Astronomers capture a small fraction of these detonations because they are comparatively short-lived, like fireflies flickering on a summer evening. After skyrocketing to a sudden peak in brightness, a supernova can take weeks to slowly fade away. For the past decade astronomers have been befuddled by a more curious "flash-in-the-pan" that pops up and then disappears in just a few days, not weeks. It's called a Fast-Evolving Luminous Transient (FELT). Only a few FELTs have been seen in telescopic sky surveys because they are so brief. Then along came NASA's Kepler Space Telescope that caught a FELT in the act. Kepler's outstanding ability to precisely record changes in the brightness of celestial objects was designed to look for planets across our galaxy. But a great spinoff from the observatory is to go supernova hunting too. Kelper's unique capabilities captured the properties of the blast. This allowed astronomers to exclude a range of theories about how FELTs happen, and converge on a plausible model. They conclude that the brief flash is from a vast shell of material around a supernova that abruptly lights up when the supernova blast wave crashes into it. View the full article

In a cosmic tug-of-war between two dwarf galaxies orbiting the Milky Way, only NASA’s Hubble Space Telescope can see who’s winning. The players are the Large and Small Magellanic Clouds, and as they gravitationally tug at each other, one of them has pulled out a huge amount of gas from its companion. This shredded and fragmented gas, called the Leading Arm, is being devoured by the Milky Way and feeding new star birth in our galaxy. But which dwarf galaxy is doing the pulling, and whose gas is now being feasted upon? Scientists used Hubble’s ultraviolet vision to chemically analyze the gas in the Leading Arm and determine its origin. After years of debate, we now have the answer to this “whodunit” mystery. View the full article

The adventuring cinema archeologist Indiana Jones would be delighted to find a long-sought relic in his own backyard. Astronomers have gotten lucky enough to achieve such a quest. They identified a very rare and odd assemblage of stars that has remained essentially unchanged for the past 10 billion years. The diffuse stellar island provides valuable new insights into the origin and evolution of galaxies billions of years ago. As far as galaxy evolution goes, this object is clearly a case of “arrested development.” The galaxy, NGC 1277, started its life with a bang long ago, ferociously churning out stars 1,000 times faster than seen in our own Milky Way today. But it abruptly went quiescent as the baby boomer stars aged and grew ever redder. Though Hubble has seen such “red and dead” galaxies in the early universe, one has never been conclusively found nearby. Where the early galaxies are so distant, they are just red dots in Hubble deep-sky images. NGC 1277 offers a unique opportunity to see one up close and personal. The telltale sign of the galaxy’s state lies in the ancient globular clusters that swarm around it. Massive galaxies tend to have both metal-poor (appearing blue) and metal-rich (appearing red) globular clusters. The red clusters are believed to form as the galaxy forms, while the blue clusters are later brought in as smaller satellites are swallowed by the central galaxy. However, NGC 1277 is almost entirely lacking in blue globular clusters. The red clusters are the strongest evidence that the galaxy went out of the star-making business long ago. However, the lack of blue clusters suggests that NGC 1277 never grew further by gobbling up surrounding galaxies. View the full article

Finding lots of dust around stars may not sound like anything astronomers would get excited about. The universe is a dusty place. But dust around a young star can be evidence that planet formation is taking place. This isn’t a new idea. In 1755, German Philosopher Immanuel Kant first proposed that planets formed around our Sun in a debris disk of gas and dust. Astronomers imagined that this process might take place around other stars. They had to wait until the early 1980s for the first observational evidence for a debris disk around any star to be uncovered. An edge-on debris disk was photographed around the southern star Beta Pictoris. Beta Pictoris remained the poster child for such debris systems until the late 1990s when the Hubble Space Telescope’s second-generation instruments, which had the capability of blocking out the glare of a central star, allowed many more disks to be photographed. Now, they are thought to be common around stars. About 40 such systems have been imaged to date, largely by Hubble. In this recent image, Hubble uncovers a vast, complex dust structure, about 150 billion miles across, enveloping the young star HR 4796A. A bright, narrow inner ring of dust is already known to encircle the star, based on much earlier Hubble photographs. It may have been corralled by the gravitational pull of an unseen giant planet. This newly discovered huge dust structure around the system may have implications for what this yet-unseen planetary system looks like around the 8-million-year-old star, which is in its formative years of planet construction. View the full article

Using Hubble and Spitzer space telescopes, scientists studied the “hot Saturn” called WASP-39b — a hot, bloated, Saturn-mass exoplanet located about 700 light-years from Earth. By dissecting starlight filtering through the planet’s atmosphere into its component colors, the team found clear evidence for a large amount of water vapor. In fact, WASP-39b has three times as much water as Saturn does. Although the researchers predicted they’d see water, they were surprised by how much they found. This suggests that the planet formed farther out from the star, where it was bombarded by a lot of icy material. Because WASP-39b has so much more water than Saturn, it must have formed differently from our famously ringed neighbor. View the full article

The good news: Astronomers have made the most precise measurement to date of the rate at which the universe is expanding since the big bang. The possibly unsettling news: This may mean that there is something unknown about the makeup of the universe. The new numbers remain at odds with independent measurements of the early universe's expansion. Is something unpredicted going on in the depths of space? Astronomers have come a long way since the early 1900s when they didn't have a clue that we lived in an expanding universe. Before this could be realized, astronomers needed an accurate celestial measuring stick to calculate distances to far-flung objects. At that time, faint, fuzzy patches of light that we now know as galaxies were thought by many astronomers to be objects inside our Milky Way. But, in 1913, Harvard astronomer Henrietta Leavitt discovered unique pulsating stars that maintain a consistent brightness no matter where they reside. Called Cepheid variables, these stars became reliable yardsticks for astronomers to measure cosmic distances from Earth. A few years later, building on Leavitt's pioneering work, astronomer Edwin Hubble found a Cepheid variable star in the Andromeda nebula. By measuring the star's tremendous distance, Hubble proved that the nebula was really an entire galaxy — a separate island of billions of stars far outside our Milky Way. He went on to find many more galaxies across space. When he used Cepheid variables to measure galaxy distances, he found that the farther away a galaxy is, the faster it appears to be receding from us. This led him to the monumental discovery that our universe is uniformly expanding in all directions. And, even the universe's age, which today we know is 13.8 billion years, could be calculated from the expansion rate. Little would Leavitt have imagined that her Cepheid variable work would become the solid bottom rung of a cosmic distance ladder of interlinked techniques that would allow for measurements across billions of light-years. The latest Hubble telescope results that solidify the cosmic ladder confirm a nagging discrepancy showing the universe is expanding faster now than was expected from its trajectory seen shortly after the big bang. Researchers suggest that there may be new physics at work to explain the inconsistency. One idea is that the universe contains a new high-speed subatomic particle. Another possibility is that dark energy, already known to be accelerating the cosmos, may be shoving galaxies away from each other with even greater — or growing — strength. The Hubble study extends the number of Cepheid stars analyzed to distances of up to 10 times farther across our galaxy than previous Hubble results. The new measurements help reduce the chance that the discrepancy in the values is a coincidence to 1 in 5,000. View the full article

Three billion miles away on the farthest known major planet in our solar system, an ominous, stinky, dark storm is shrinking out of existence as seen in pictures of Neptune taken by the Hubble Space Telescope. Immense dark storms on Neptune were first discovered in the late 1980s by the Voyager 2 spacecraft. Since then, only Hubble has tracked these elusive features that play a game of peek-a-boo over the years. Hubble found two dark storms that appeared in the mid-1990s and then vanished. This latest storm was first seen in 2015, but is now shrinking away. The dark spot material may be hydrogen sulfide, with the pungent smell of rotten eggs. View the full article

Only 40 light-years away — a stone’s throw on the scale of our galaxy — several Earth-sized planets orbit the red dwarf star TRAPPIST-1. Four of the planets lie in the star’s habitable zone, a region at a distance from the star where liquid water, the key to life as we know it, could exist on the planets’ surfaces. Astronomers using NASA's Hubble Space Telescope have conducted the first spectroscopic survey of these worlds. Hubble reveals that at least three of the exoplanets do not seem to contain puffy, hydrogen-rich atmospheres similar to gaseous planets such as Neptune. This means the atmospheres may be more shallow and rich in heavier gases like those found in Earth’s atmosphere, such as carbon dioxide, methane, and oxygen. Astronomers plan to use NASA’s James Webb Space Telescope, scheduled to launch in 2019, to probe deeper into the planetary atmospheres to search for the presence of such elements that could offer hints of whether these far-flung worlds are habitable. View the full article

Using NASA's Hubble Space Telescope to peer deep into the vast stellar nursery called the Orion Nebula, astronomers searched for small, faint bodies. What they found was the largest population yet of brown dwarfs — objects that are more massive than planets but do not shine like stars. Researchers identified 17 brown dwarf companions to red dwarf stars, one brown dwarf pair, and one brown dwarf with a planetary companion. They also found three giant planets, including a binary system where two planets orbit each other in the absence of a parent star. This survey could only be done with Hubble’s exceptional resolution and infrared sensitivity. View the full article

Every star has a story to tell. Study a star and it will give you information about its composition, age, and possibly even clues to where it first formed. The stars residing in the oldest structure of our Milky Way galaxy, the central bulge, offer insight into how our pinwheel-shaped island of myriad stars evolved over billions of years. Think of our Milky Way as a pancake-shaped structure with a big round dollop of butter in the middle — that would be our galaxy’s central hub. For many years, astronomers had a simple view of our Milky Way’s bulge as a quiescent place composed of old stars, the earliest homesteaders of our galaxy. A new analysis of about 10,000 normal Sun-like stars in the bulge reveals that our galaxy’s hub is a dynamic environment of variously aged stars zipping around at different speeds, like travelers bustling about a busy airport. This conclusion is based on nine years’ worth of archival data from the Hubble Space Telescope. The faster-moving and later-generation stars may have arrived at the hub through our Milky Way cannibalizing smaller galaxies. They mingle with a different population of older, slowing-moving stars. Currently, only Hubble has sharp enough resolution to simultaneously measure the motions of thousands of Sun-like stars at the bulge's distance from Earth. View the full article

As powerful as NASA’s Hubble and Spitzer space telescopes are, they need a little help from nature in seeking out the farthest, and hence earliest galaxies that first appeared in the universe after the big bang. This help comes from a natural zoom lens in the universe, formed by the warping of space by intense gravitational fields. The most powerful “zoom lenses” out there are formed by very massive foreground clusters that bend space like a bowling ball rolling across a soft mattress. The lens boosts the brightness of distant background objects. The farthest candidates simply appear as red dots in Hubble photos because of their small size and great distance. However, astronomers got very lucky when they looked at galaxy cluster SPT-CL J0615-5746. Embedded in the photo is an arc-like structure that is not only the amplified image of a background galaxy, but an image that has been smeared into a crescent-shape. This image allowed astronomers to estimate that the diminutive galaxy weighs in at no more than 3 billion solar masses (roughly 1/100th the mass of our fully grown Milky Way galaxy). It is less than 2,500 light-years across, half the size of the Small Magellanic Cloud, a satellite galaxy of our Milky Way. The object is considered prototypical of young galaxies that emerged during the epoch shortly after the big bang. Hubble’s clarity, combined with Spitzer’s infrared sensitivity to light reddened by the expanding universe, allowed for the object’s vast distance to be calculated. View the full article

Supermassive black holes, weighing millions of times as much as our Sun, are gatherers not hunters. Embedded in the hearts of galaxies, they will lie dormant for a long time until the next meal happens to come along. The team of astronomers using observations from the Hubble Space Telescope, the Chandra X-ray Observatory, and as well as the W.M. Keck Observatory in Mauna Kea, Hawaii, and the Apache Point Observatory (APO) near Sunspot, New Mexico, zeroed in on a flickering black hole. A black hole in the center of galaxy SDSS J1354+1327, located about 800 million light-years away, appears to have consumed large amounts of gas while blasting off an outflow of high-energy particles. The fresh burst of fuel might have been supplied by a bypassing galaxy. The outflow eventually switched off then turned back on about 100,000 years later. This is strong evidence that accreting black holes can switch their power output off and on again over timescales that are short compared to the 13.8-billion-year age of the universe. View the full article

By combining the visible and infrared capabilities of the Hubble and Spitzer space telescopes, astronomers and visualization specialists from NASA's Universe of Learning program have created a spectacular, three-dimensional, fly-through movie of the magnificent Orion nebula, a nearby stellar nursery. Using actual scientific data along with Hollywood techniques, a team at the Space Telescope Science Institute in Baltimore, Maryland, and the Caltech/IPAC in Pasadena, California, has produced the best and most detailed multi-wavelength visualization yet of the Orion nebula. The three-minute movie allows viewers to glide through the picturesque star-forming region and experience the universe in an exciting new way. View the full article

It's beginning to look a lot like the holiday season in this NASA Hubble Space Telescope image of a blizzard of stars, which resembles a swirling snowstorm in a snow globe. The stars are residents of the globular star cluster Messier 79, or M79, located 41,000 light-years from Earth, in the constellation Lepus. The cluster is also known as NGC 1904. View the full article

Voices reverberating off mountains and the sound of footsteps bouncing off walls are examples of an echo. Echoes happen when sound waves ricochet off surfaces and return to the listener. Space has its own version of an echo. It’s not made with sound but with light, and occurs when light bounces off dust clouds. The Hubble telescope has just captured one of these cosmic echoes, called a “light echo,” in the nearby starburst galaxy M82, located 11.4 million light-years away. A movie assembled from more than two years’ worth of Hubble images reveals an expanding shell of light from a supernova explosion sweeping through interstellar space three years after the stellar blast was discovered. The “echoing” light looks like a ripple expanding on a pond. The supernova, called SN 2014J, was discovered on Jan. 21, 2014. A light echo occurs because light from the stellar blast travels different distances to arrive at Earth. Some light comes to Earth directly from the supernova blast. Other light is delayed because it travels indirectly. In this case, the light is bouncing off a huge dust cloud that extends 300 to 1,600 light-years around the supernova and is being reflected toward Earth. So far, astronomers have spotted only 15 light echoes around supernovae outside our Milky Way galaxy. Light echo detections from supernovae are rarely seen because they must be nearby for a telescope to resolve them. View the full article

Photobombing asteroids from our solar system have snuck their way into this deep image of the universe taken by NASA’s Hubble Space Telescope. These asteroids are right around the corner in astronomical terms, residing roughly 160 million miles from Earth. Yet they’ve horned their way into this picture of thousands of galaxies scattered across space and time at inconceivably farther distances. View the full article

Travelers to the nightside of exoplanet Kepler-13Ab should pack an umbrella because they will be pelted with precipitation. But it's not the kind of watery precipitation that falls on Earth. On this alien world, the precipitation is in the form of sunscreen. Ironically, the sunscreen (titanium dioxide) is not needed on this side of the planet because it never receives any sunlight. But bottling up some sunlight protection is a good idea if travelers plan on visiting the sizzling hot, permanent dayside, which always faces its star. Visitors won't find any desperately needed sunscreen on this part of the planet. Astronomers didn't detect the titanium dioxide directly. They used Hubble to find that the atmospheric temperature grows increasingly colder with altitude on the dayside of Kepler-13Ab, which was contrary to what they had expected. On this super-hot dayside, titanium dioxide should exist as a gas, called titanium oxide. If titanium oxide were present in the daytime atmosphere, it would absorb light and heat the upper atmosphere. Instead, high winds carry the titanium oxide around to the permanently dark side of the planet where it condenses to form clouds and precipitation, and rains down as titanium dioxide. The planet's crushing gravity pulls all the titanium dioxide so far down it can't be recycled back into the upper atmosphere on the daytime side. The Hubble observations represent the first time astronomers have detected this precipitation process, called a "cold trap," on an exoplanet. Kepler-13Ab is one of the hottest known planets, with a dayside temperature of nearly 5,000 degrees Fahrenheit. The Kepler-13 system resides 1,730 light-years from Earth. View the full article