The most crowded collision of galaxy clusters has been identified by combining information from three different telescopes. This result gives scientists a chance to learn what happens when some of the largest objects in the universe go at each other in a cosmic free-for-all. Using data from NASA's Chandra X-ray Observatory, Hubble Space Telescope, and the Keck Observatory in Hawaii, astronomers were able to determine the three-dimensional geometry and motion in the system MACS J0717.5+3745 (or MACS J0717, for short), located about 5.4 billion light-years from Earth.
Hubble Celebrates Its 19th Anniversary with a "Fountain of Youth"
Over the past 19 years Hubble has taken dozens of exotic pictures of galaxies going "bump in the night" as they collide with each other and have a variety of close encounters of the galactic kind. Just when you thought these interactions couldn't look any stranger, this image of a trio of galaxies, called Arp 194, looks like one of the galaxies has sprung a leak. The bright blue streamer is really a stretched spiral arm full of newborn blue stars. This typically happens when two galaxies interact and gravitationally tug at each other.
Resembling a pair of owl eyes, the two nuclei of the colliding galaxies can be seen in the process of merging at the upper left. The blue bridge looks like it connects to a third galaxy. In reality the galaxy is in the background and not connected at all. Hubble's sharp view allows astronomers to try and visually sort out what are foreground and background objects when galaxies, superficially, appear to overlap. This picture was issued to celebrate the 19th anniversary of the launch of the Hubble Space Telescope aboard the space shuttle Discovery in 1990. During the past 19 years Hubble has made more than 880,000 observations and snapped over 570,000 images of 29,000 celestial objects.
Space Telescope Science Institute Astrophysicist Elected to National Academy of Sciences
Adam Riess was among 72 scientists elected today to membership in the National Academy of Sciences at the organization's 146th annual meeting, held in Washington, D.C. Riess, an astronomer at the Space Telescope Science Institute (STScI) and professor in the Henry A. Rowland Department of Physics and Astronomy in the Zanvyl Krieger School of Arts and Sciences, joins 20 other Johns Hopkins faculty members currently in the Academy, an honorary society that advises the government on scientific matters.
Bursts of star making in a galaxy have been compared to a Fourth of July fireworks display: They occur at a fast and furious pace, lighting up a region for a short time before winking out. But these fleeting starbursts are only pieces of the story, astronomers say. An analysis of archival images of small, or dwarf, galaxies taken by NASA's Hubble Space Telescope suggests that starbursts, intense regions of star formation, sweep across the whole galaxy and last 100 times longer than astronomers thought. The longer duration may affect how dwarf galaxies change over time, and therefore may shed light on galaxy evolution.
Refined Hubble Constant Narrows Possible Explanations for Dark Energy
Less than 100 years ago scientists didn't know if the universe was coming or going, literally. It even fooled the great mind of Albert Einstein. He assumed the universe must be static. But to keep the universe from collapsing under gravity like a house of cards, Einstein hypothesized there was a repulsive force at work, called the cosmological constant, that counterbalanced gravity's tug. Along came Edwin Hubble in 1923 who found that galaxies were receding from us at a proportional rate, called the Hubble constant, which meant the universe was uniformly expanding, so there was no need to shore it up with any mysterious force from deep space. In measuring how this expansion was expected to slow down over time, 11 years ago, two studies, one led by Adam Riess of the Space Telescope Science Institute and the Johns Hopkins University and Brian Schmidt of Mount Stromlo Observatory, and the other by Saul Perlmutter of Lawrence Berkeley National Laboratory, independently discovered dark energy, which seems to behave like Einstein's cosmological constant.
To better characterize dark energy, Riess used Hubble Space Telescope's crisp view (combined with 2003 data from NASA's Wilkinson Microwave Anisotropy Probe, WMAP) to refine the value of the universe's expansion rate to a precision of three percent. That's a big step from 20 years ago when astronomers' estimates for the Hubble constant disagreed by a factor of two. This new value implies that dark energy really is a steady push on the universe as Einstein imagined, rather than something more effervescent (like the early inflationary universe) that changes markedly over time.
Hubble Photographs a Planetary Nebula to Commemorate Decommissioning of Super Camera
The Hubble community bids farewell to the soon-to-be decommissioned Wide Field Planetary Camera 2 (WFPC2) onboard the Hubble Space Telescope. In tribute to Hubble's longest-running optical camera, planetary nebula K 4-55 has been imaged as WFPC2's final "pretty picture."
The Space Telescope Science Institute (STScI) in Baltimore, Md., is partnering on a historic search for Earth-size planets around other stars. STScI is the data archive center for NASA's Kepler mission, a spacecraft that is undertaking a survey for Earth-size planets in our region of the galaxy. The spacecraft sent its first raw science data to STScI on June 19. The Institute's role is to convert the raw science data into files that can be analyzed by Kepler researchers and to store the files every three months in an archive.
NASA scientists have interrupted the checkout and calibration of the Hubble Space Telescope to aim the recently refurbished observatory at a new expanding spot on the giant planet Jupiter. The spot, caused by the impact of a comet or an asteroid, is changing day to day in the planet's cloud tops. The Hubble picture, taken on July 23, is the sharpest visible-light picture taken of the impact feature. The observations were made with Hubble's new camera, the Wide Field Camera 3 (WFC3). WFC3 is not yet fully calibrated, and while it is possible to obtain celestial images, the camera's full power cannot yet be realized for most observations. The WFC3 can still return meaningful science images that will complement the Jupiter pictures being taken with ground-based telescopes.
Astronomers Find Hyperactive Galaxies in the Early Universe
Even some galaxies may have been hyperactive youngsters. Looking almost 11 billion years into the past, astronomers have measured the motions of stars for the first time in a very distant galaxy. They are whirling at a speed of one million miles per hour-about twice the speed of our Sun through the Milky Way. Even stranger, the galaxies are a fraction the size of our Milky Way, and so may have evolved over billions of years into the full-grown galaxies seen around us today. Astronomers are puzzled by how galaxies like these formed. They may be what will eventually become the dense central regions of very large galaxies.
The galaxies were found by using the combined power of NASA's Hubble Space Telescope and the 8-meter Gemini South telescope in Chile. Hubble shows that the galaxies are a fraction the size of most galaxies we see today. The Gemini telescope clocks their speed by using spectroscopy. To witness the formation of these extreme galaxies astronomers plan to observe galaxies even farther back in time with Hubble's new Wide Field Camera 3.
NASA's Hubble Space Telescope is back in business, ready to uncover new worlds, peer ever deeper into space, and even map the invisible backbone of the universe. The first snapshots from the refurbished Hubble showcase the 19-year-old telescope's new vision. Topping the list of exciting new views are colorful multi-wavelength pictures of far-flung galaxies, a densely packed star cluster, an eerie "pillar of creation," and a "butterfly" nebula. With its new imaging camera, Hubble can view galaxies, star clusters, and other objects across a wide swath of the electromagnetic spectrum, from ultraviolet to near-infrared light. A new spectrograph slices across billions of light-years to map the filamentary structure of the universe and trace the distribution of elements that are fundamental to life. The telescope's new instruments also are more sensitive to light and can observe in ways that are significantly more efficient and require less observing time than previous generations of Hubble instruments. NASA astronauts installed the new instruments during the space shuttle servicing mission in May 2009. Besides adding the instruments, the astronauts also completed a dizzying list of other chores that included performing unprecedented repairs on two other science instruments.
Now that Hubble has reopened for business, it will tackle a whole range of observations. Looking closer to Earth, such observations will include taking a census of the population of Kuiper Belt objects residing at the fringe of our solar system, witnessing the birth of planets around other stars, and probing the composition and structure of the atmospheres of other worlds. Peering much farther away, astronomers have ambitious plans to use Hubble to make the deepest-ever portrait of the universe in near-infrared light. The resulting picture may reveal never-before-seen infant galaxies that existed when the universe was less than 500 million years old. Hubble also is now significantly more well-equipped to probe and further characterize the behavior of dark energy, a mysterious and little-understood repulsive force that is pushing the universe apart at an ever-faster rate.
NASA's Hubble Space Telescope has made a series of observations immediately preceding and following the Lunar Crater Observation and Sensing Satellite (LCROSS) Centaur rocket stage and shepherding spacecraft impacts at the lunar south pole, on October 9 at 7:31 and 7:35 a.m. EDT.
Dr. Rodger Doxsey, head of the Space Telescope Science Institute's (STScI) Hubble Mission Office, passed away on October 13 after a prolonged illness. The New York native was 62 years old.
Doxsey oversaw Hubble science operations at STScI in Baltimore, Md., for nearly three decades. Astronomers credit Doxsey for being one of the key Hubble program people who had a working knowledge of the extremely complex Hubble Space Telescope from top to bottom. Doxsey dedicated his career to making Hubble a success, working closely with the scientists and engineers at the institute that operate the telescope, the engineers at NASA's Goddard Space Flight Center in Greenbelt, Md., and the scientists from around the world who use the telescope.
Hubble Image Showcases Star Birth in M83, the Southern Pinwheel
The spectacular new camera installed on NASA's Hubble Space Telescope during Servicing Mission 4 in May has delivered the most detailed view of star birth in the graceful, curving arms of the nearby spiral galaxy M83.
Nicknamed the Southern Pinwheel, M83 is undergoing more rapid star formation than our own Milky Way galaxy, especially in its nucleus. The sharp "eye" of the Wide Field Camera 3 (WFC3) has captured hundreds of young star clusters, ancient swarms of globular star clusters, and hundreds of thousands of individual stars, mostly blue supergiants and red supergiants. The image at right, taken in August 2009, is Hubble's close-up view of the myriad stars near the galaxy's core, the bright whitish region at far right. An image of the entire galaxy, taken by the European Southern Observatory's Wide Field Imager on the ESO/MPG 2.2-meter telescope at La Silla, Chile, is shown at left. The white box outlines Hubble's view.
NASA's Great Observatories Celebrate International Year of Astronomy
A never-before-seen view of the turbulent heart of our Milky Way galaxy is being unveiled by NASA on Nov. 10. This event will commemorate the 400 years since Galileo first turned his telescope to the heavens in 1609. In celebration of this International Year of Astronomy, NASA is releasing images of the galactic center region as seen by its Great Observatories to more than 150 planetariums, museums, nature centers, libraries, and schools across the country.
The magnificent galaxy NGC 4710 is tilted nearly edge-on to our view from Earth. This perspective allows astronomers to easily distinguish the central bulge of stars from its pancake-flat disk of stars, dust, and gas. What's striking in the image is a ghostly "X" pattern of stars. This natural-color photo was taken with the Hubble Space Telescope's Advanced Camera for Surveys on January 15, 2006.
Hubble's Deepest View of Universe Unveils Never-Before-Seen Galaxies
NASA's Hubble Space Telescope has made the deepest image of the universe ever taken in near-infrared light. The faintest and reddest objects in the image are galaxies that formed 600 million years after the Big Bang. No galaxies have been seen before at such early times. The new deep view, taken in late August 2009, also provides insights into how galaxies grew in their formative years early in the universe's history. The image was taken in the same region as the Hubble Ultra Deep Field (HUDF), which was taken in 2004 and is the deepest visible-light image of the universe. Hubble's newly installed Wide Field Camera 3 (WFC3) collects light from near-infrared wavelengths and therefore looks even deeper into the universe, because the light from very distant galaxies is stretched out of the ultraviolet and visible regions of the spectrum into near-infrared wavelengths by the expansion of the universe.
Hubble's Festive View of a Grand Star-Forming Region
Just in time for the holidays: a Hubble Space Telescope picture postcard of hundreds of brilliant blue stars wreathed by warm, glowing clouds. The festive portrait is the most detailed view of the largest stellar nursery in our local galactic neighborhood. The massive, young stellar grouping, called R136, is only a few million years old and resides in the 30 Doradus Nebula, a turbulent star-birth region in the Large Magellanic Cloud (LMC), a satellite galaxy of our Milky Way. There is no known star-forming region in our galaxy as large or as prolific as 30 Doradus. Many of the diamond-like icy blue stars are among the most massive stars known. Several of them are over 100 times more massive than our Sun. These hefty stars are destined to pop off, like a string of firecrackers, as supernovas in a few million years.
The image, taken in ultraviolet, visible, and red light by Hubble's Wide Field Camera 3, spans about 100 light-years. The nebula is close enough to Earth that Hubble can resolve individual stars, giving astronomers important information about the birth and evolution of stars in the universe. The Hubble observations were taken Oct. 20-27, 2009. The blue color is light from the hottest, most massive stars; the green from the glow of oxygen; and the red from fluorescing hydrogen.
Hubble Finds Smallest Kuiper Belt Object Ever Seen
NASA's Hubble Space Telescope has discovered the smallest object ever seen in visible light in the Kuiper Belt, a vast ring of icy debris that is encircling the outer rim of the solar system just beyond Neptune.
The needle-in-a-haystack object found by Hubble is only 3,200 feet across and a whopping 4.2 billion miles away. The smallest Kuiper Belt Object (KBO) seen previously in reflected light is roughly 30 miles across, or 50 times larger.
STScI Senior Astrophysicist Mario Livio Elected AAAS Fellow
In November, the American Association for the Advancement of Science (AAAS) Council elected Space Telescope Science Institute's senior astrophysicist Mario Livio and 530 other AAAS members as Fellows of AAAS. Election as a Fellow is an honor bestowed upon AAAS members by their peers. These individuals will be recognized for their contributions to science and technology at the Fellows Forum to be held on February 20, 2010, during the AAAS Annual Meeting in San Diego, Calif. The new Fellows will receive a certificate and a blue and gold rosette in recognition of their distinguished efforts to advance science or its applications. Dr. Livio is cited for his "distinguished contributions to astrophysics through research on stars and galaxies and through communicating and interpreting science and mathematics to the public." The new Fellows are being announced in the AAAS News and Notes section of today's issue of the journal Science.
Hubble Provides Interstellar Road Map for Voyagers' Galactic Trek
In 1977, NASA's Voyager 1 and 2 spacecraft began their pioneering journey across the solar system to visit the giant outer planets. Now, the Voyagers are hurtling through unexplored territory on their road trip beyond our solar system. Along the way, they are measuring the interstellar medium, the mysterious environment between stars that is filled with the debris from long-dead stars. NASA's Hubble Space Telescope is providing the road map, by measuring the material along the probes' trajectories as they move through space. Hubble finds a rich, complex interstellar ecology, containing multiple clouds of hydrogen, laced with other elements. Hubble data, combined with the Voyagers, have also provided new insights into how our sun travels through interstellar space.
