In this view of the center of the magnificent barred spiral galaxy NGC 1512, the Hubble telescope reveals a stunning 2,400 light-year-wide circle of infant star clusters. Astronomers generally believe that the giant bar, which is too faint to be seen in this image, funnels the gas to the inner ring, where massive stars are formed within numerous star clusters. Located 30 million light-years away, NGC 1512 is a neighbor of our Milky Way galaxy.
Bigger, Better Catalog Unveils Half a Billion Celestial Objects
It's a very big universe out there, and an astronomer's work is never done when it comes to simply counting and cataloging the sheer number of stars in the heavens. Completing a seven-year effort at digitizing the entire sky for a second time, astronomers at the Space Telescope Science Institute and the Osservatorio Astronomico di Torino are releasing the Guide Star Catalog II. This new version, which replaces the historic 1989 catalog, provides important information on nearly one-half billion stars - over 20 times as many as the original Guide Star Catalog.
Iridescent Glory of Nearby Planetary Nebula Showcased on Astronomy Day
This photograph of the coil-shaped Helix Nebula is one of the largest and most detailed celestial images ever made. The composite picture is a seamless blend of ultra-sharp images from NASA's Hubble Space Telescope combined with the wide view of the Mosaic Camera on the National Science Foundation's 0.9-meter telescope at Kitt Peak National Observatory near Tucson, Ariz. The image shows a fine web of filamentary "bicycle-spoke" features embedded in the colorful red and blue ring of gas. At 650 light-years away, the Helix is one of the nearest planetary nebulae to Earth. A planetary nebula is the glowing gas around a dying, Sun-like star.
Brighter Neptune Suggests a Planetary Change of Seasons
Springtime is blooming on Neptune! This might sound like an oxymoron because Neptune is the farthest and coldest of the major planets. But observations by NASA's Hubble Space Telescope reveal an increase in Neptune's brightness in the southern hemisphere. Astronomers consider this increase a harbinger of seasonal change. The observations, made over six years, show a distinct increase in the amount and brightness of the clouds encircling the planet's southern hemisphere.
These two images, taken 11 hours apart with NASA's Hubble Space Telescope, reveal two nearly opposite sides of Mars. Hubble snapped these photos as the red planet was making its closest approach to Earth in almost 60,000 years. Mars completed nearly one half a rotation between the two observations.
Hubble Approaches the Final Frontier: The Dawn of Galaxies
Detailed analyses of mankind's deepest optical view of the universe, the Hubble Ultra Deep Field (HUDF), by several expert teams have at last identified, what may turn out to be, the earliest star-forming galaxies. Astronomers are now debating whether the hottest stars in these early galaxies may have provided enough radiation to "lift a curtain" of cold, primordial hydrogen that cooled after the big bang. This is a problem that has perplexed astronomers over the past decade, and NASA's Hubble Space Telescope has at last glimpsed what could be the "end of the opening act" of galaxy formation. These faint sources illustrate how astronomers can begin to explore when the first galaxies formed and what their properties might be.
But even though Hubble has looked 95 percent of the way back to the beginning of time, astronomers agree that's not far enough.
NASA's Great Observatories May Unravel 400-Year Old Supernova Mystery
Four hundred years ago, sky watchers, including the famous astronomer Johannes Kepler, were startled by the sudden appearance of a "new star" in the western sky, rivaling the brilliance of the nearby planets. Now, astronomers using NASA's three Great Observatories are unraveling the mysteries of the expanding remains of Kepler's supernova, the last such object seen to explode in our Milky Way galaxy.
Stellar Survivor from 1572 A.D. Explosion Supports Supernova Theory
An international team of astronomers is announcing today that they have identified the probable surviving companion star to a titanic supernova explosion witnessed in the year 1572 by the great Danish astronomer Tycho Brahe and other astronomers of that era.
This discovery provides the first direct evidence supporting the long-held belief that Type Ia supernovae come from binary star systems containing a normal star and a burned-out white dwarf star. The normal star spills material onto the dwarf, which eventually triggers an explosion.
At first glance, Jupiter looks like it has a mild case of the measles. Five spots - one colored white, one blue, and three black - are scattered across the upper half of the planet. Closer inspection by NASA's Hubble Space Telescope reveals that these spots are actually a rare alignment of three of Jupiter's largest moons - Io, Ganymede, and Callisto - across the planet's face. In this image, the telltale signatures of this alignment are the shadows [the three black circles] cast by the moons. Io's shadow is located just above center and to the left; Ganymede's on the planet's left edge; and Callisto's near the right edge. Only two of the moons, however, are visible in this image. Io is the white circle in the center of the image, and Ganymede is the blue circle at upper right. Callisto is out of the image and to the right.
Spitzer and Hubble Capture Evolving Planetary Systems
Two of NASA's Great Observatories, the Spitzer Space Telescope and the Hubble Space Telescope, have provided astronomers an unprecedented look at dusty planetary debris around stars the size of our sun. Spitzer has discovered for the first time dusty discs around mature, sun-like stars known to have planets. Hubble captured the most detailed image ever of a brighter disc circling a much younger sun-like star. The findings offer "snapshots" of the process by which our own solar system evolved, from its dusty and chaotic beginnings to its more settled present-day state.
Debris disks are composed of the shattered remnants of small bodies such as comets and asteroids that collided as they orbited the star. A similar, though much less dense cloud of dust orbits our Sun. Large, gaseous planets like Jupiter might already exist in such systems, while much smaller rocky planets like the Earth may be just starting to form.
Looks can be deceiving, especially when it comes to celestial objects like galaxies and nebulas. These objects are so far away that astronomers cannot see their three-dimensional structure. The Helix Nebula, for example, resembles a doughnut in colorful images. Earlier images of this complex object – the gaseous envelope ejected by a dying, sun-like star -- did not allow astronomers to precisely interpret its structure. One possible interpretation was that the Helix's form resembled a snake-like coil. Now, a team of astronomers using NASA's Hubble Space Telescope has established that the Helix's structure is even more perplexing. Their evidence suggests that the Helix consists of two disks nearly perpendicular to each other.
Hubble's Infrared Eyes Home in on Suspected Extrasolar Planet
The Hubble Space Telescope's near-infrared vision is hot on the trail of a possible planetary companion to a relatively bright young brown dwarf located 225 light-years away in the southern constellation Hydra. Astronomers at the European Southern Observatory's Very Large Telescope (VLT) in Chile detected the planet candidate in April 2004 with infrared observations. The astronomers spotted a faint companion object to the brown dwarf, called 2MASSWJ 1207334-393254 (2M1207). They suspect the companion is a planet because it is dimmer and cooler than the brown dwarf. Because a planet beyond our solar system has never been imaged directly, this remarkable observation required Hubble's unique abilities to perform follow-up observations to test and validate if the object is indeed a planet. Based on the VLT and Hubble observations, astronomers are 99 percent sure that the companion is orbiting the brown dwarf.
Astronomers using NASA's Hubble Space Telescope have uncovered for the first time a population of embryonic stars in the Small Magellanic Cloud, a companion galaxy of our Milky Way. Hubble's exquisite sharpness plucked out an underlying population of embryonic stars embedded in the nebula NGC 346 that are still forming from gravitationally collapsing gas clouds. They have not yet ignited their hydrogen fuel to sustain nuclear fusion. The smallest of these infant stars is only half the mass of our Sun.
Hubble Celebrates 15th Anniversary with Spectacular New Images
During the 15 years NASA's Hubble Space Telescope has orbited the Earth, it has taken more than 700,000 photos of the cosmos; images that have awed, astounded and even confounded astronomers and the public.
NASA released new views today of two of the most well-known objects Hubble has ever observed: the Whirlpool Galaxy (spiral galaxy M51)
and the Eagle Nebula
. These new images are among the largest and sharpest Hubble has ever taken. They were made with Hubble's newest camera, the Advanced Camera for Surveys (ACS). The images are so incredibly sharp, they could be enlarged to billboard size and still retain stunning details.
For the 15th anniversary, scientists used the ACS to record a new region of the eerie-looking Eagle Nebula. The Eagle Nebula image reveals a tall, dense tower of gas being sculpted by ultraviolet light from a group of massive, hot stars. The new Whirlpool Galaxy image showcases the spiral galaxy's classic features, from its curving arms, where newborn stars reside, to its yellowish central core that serves as home for older stars. A feature of considerable interest is the companion galaxy located at the end of one of the spiral arms.
Elusive Planet Reshapes a Ring Around Neighboring Star
The top view, taken by NASA's Hubble Space Telescope is the most detailed visible-light image ever taken of a narrow, dusty ring around the nearby star Fomalhaut (HD 216956). The image offers the strongest evidence yet that an unruly and unseen planet may be gravitationally tugging on the ring. The left part of the ring is outside the telescope's view. Hubble unequivocally shows that the center of the ring is a whopping 1.4 billion miles (15 astronomical units) away from the star. This is a distance equal to nearly halfway across our solar system. The geometrically striking ring, tilted obliquely toward Earth, would not have such a great offset if it were simply being influenced by Fomalhaut's gravity alone.
The view at bottom points out important features in the image, such as the ring's inner and outer edges. Astronomers used the Advanced Camera for Surveys' (ACS) coronagraph aboard Hubble to block out the light from the bright star so they could see the faint ring. The dot near the ring's center marks the star's location. Despite the coronagraph, some light from the star is still visible in this image, as can be seen in the wagon wheel-like spokes that form an inner ring around Fomalhaut.
Hubble Captures Deep Impact's Collision with Comet
NASA's Hubble Space Telescope captured the dramatic effects of the collision early July 4 between an 820-pound projectile released by the Deep Impact spacecraft and comet 9P/Tempel 1. This sequence of images shows the comet before and after the impact. The visible-light images were taken by the Advanced Camera for Surveys' High Resolution Camera.
Hubble Pinpoints Doomed Star that Explodes as Supernova
Amidst the glitter of billions of stars in the majestic spiral galaxy called the Whirlpool (M51), a massive star abruptly ends its life in a brilliant flash of light. NASA's Hubble Space Telescope snapped images of the exploding star, called supernova (SN) 2005cs, 12 days after its discovery. Astronomers then compared those photos with Hubble images of the same region before the supernova blast to pinpoint the progenitor star (the star that exploded).
Hubble Finds Mysterious Disk of Blue Stars Around Black Hole
Astronomers using NASA's Hubble Space Telescope have identified the source of a mysterious blue light surrounding a supermassive black hole in our neighboring Andromeda Galaxy (M31). Though the light has puzzled astronomers for more than a decade, the new discovery makes the story even more mysterious. The blue light is coming from a disk of hot, young stars that are whipping around the black hole in much the same way as planets in our solar system are revolving around the Sun. Astronomers are perplexed about how the pancake-shaped disk of stars could form so close to a giant black hole. Andromeda and its complex core can be seen in the illustration and two images [above]. The illustration [lower, right] shows the disk of blue stars nested inside a larger ring of red stars. The Hubble photo [upper, right] reveals Andromeda's bright core. The image at left shows the entire galaxy.
Spitzer and Hubble Team Up to Find "Big Baby" Galaxies in the Newborn Universe
Astronomers have used the penetrating power of two of NASA's Great Observatories, the Spitzer and Hubble Space Telescopes, to identify one of the farthest and most massive galaxies that once inhabited the early universe. Conventional wisdom is that galaxies should have grown up more slowly, like streams merging to form rivers. But this galaxy appears to have grown very quickly, within the first few hundred million years after the Big Bang. By contrast, our Milky Way galaxy took billions of years to grow to its current size, through devouring smaller galaxies. The galaxy was pinpointed among approximately 10,000 others in the Hubble Ultra Deep Field (UDF), presently the farthest optical and infrared portrait of the universe ever taken.
NASA has enlisted the Hubble Space Telescope's unique "vision" capabilities for making a new class of science observations of the Moon that support future human exploration. Hubble's exquisite resolution and sensitivity to ultraviolet light, which is reflected off the Moon's surface materials, have allowed Hubble to begin to search for the presence of important minerals that may be critical for the establishment of sustained human presence on the Moon. Preliminary assessment of these new Hubble observations suggests new patterns in the abundance of titanium and iron oxides, both of which are sources of oxygen, a key ingredient for life, and an essential ingredient for human exploration. Hubble's Advanced Camera for Surveys imaged Aristarchus crater and nearby Schroter's Valley rille on Aug. 21, 2005. These images reveal fine-scale details of the crater's interior and exterior in ultraviolet and visible wavelengths at a scale of approximately 165 to 330 feet (50 to 100 meters) per picture element. These new ultraviolet-light observations, after being compared and calibrated against Hubble's ultraviolet-light observations of the Apollo 15 and 17 landing regions, will be used to quantify abundances of the titanium-bearing oxide ilmenite.
