Hubble Provides Infrared View of Moon, Ring, and Clouds
Probing Jupiter's atmosphere for the first time, the Hubble telescope's infrared camera is providing a sharp glimpse of the planet's ring, moon, and high-altitude clouds.
The presence of methane in Jupiter's hydrogen- and helium-rich atmosphere has allowed Hubble to plumb Jupiter's atmosphere, revealing bands of high-altitude clouds. Visible-light observations cannot provide a clear view of these high clouds because the underlying clouds reflect so much visible light that the higher-level clouds are indistinguishable from the lower layer.
One Star's Loss is Another's Gain: Hubble Captures Brief Moment in Life of Lively Duo
Some stars in double-star systems have found a quick way to lose weight by dumping their extra pounds onto their companions. Astronomers using the Hubble telescope have discovered such a case in the double-star system Phi Persei. A "rapid diet" program has trimmed an aging, once massive star to a lean one solar mass, while the once mild-mannered, moderately massive companion has bulked up to a hefty nine solar masses and is spinning so violently that it's flinging gas from its surface.
Taken from the perspective of the Hubble telescope's observations of Phi Persei, this artist's depiction provides a taste of the double-star system's unstable existence. The star shedding pounds is represented as the white, semicircular object looming in the upper right of the illustration. The red, pancake-shaped object surrounding it is a gas disk. The gas is material the star is losing because of its rapid rotation. The small, hot sub-dwarf in the lower left of the illustration is the star that is benefiting from its companion's weight-loss program.
Hubble Witnesses the Final Blaze of Glory of Sun-Like Stars
The end of a Sun-like star's life was once thought to be simple: the star gracefully casts off a shell of glowing gas and then settles into a long retirement as a burned-out white dwarf.
Now, a dazzling collection of detailed views from the Hubble telescope reveals surprisingly intricate, glowing patterns spun into space by aging stars: pinwheels, lawn sprinkler-style jets, elegant goblet shapes, and even some that look like a rocket engine's exhaust. In this picture of M2-9, twin lobes of material emanate from a central, dying star. Astronomers have dubbed this object the "Twin Jet Nebula" because of the shape of the lobes. If the nebula is sliced across the star, each side appears much like a pair of exhausts from jet engines. Indeed, because of the nebula's shape and the measured velocity of the gas, in excess of 200 miles per second, astronomers believe that the description as a super-super-sonic jet exhaust is quite apt.
Astronomers Have Found a New Twist in a Suspected Proto-Planetary Disk
A telltale new warp uncovered in a vast, thin disk of dust encircling the star Beta Pictoris may be caused by the gravitational tug of a bypassing star or companion brown dwarf.
These conclusions are based on Hubble telescope pictures that reveal the dim outermost reaches of the disk, which are 7 billion miles from the central star. The top image presents the entire disk, which spans 140 billion miles edge-to-edge. An unusual flaring at the top of the right side of the disk reveals that dust has been pulled above the dense plane of the disk beyond what is observed on the left side. A detailed close-up view of the inner region of the disk [bottom picture] shows a warp in the disk. These new details support the presence of one or more planets orbiting the star.
The Hubble telescope has captured a complete view of Jupiter's northern and southern auroras. Images taken in ultraviolet light show both auroras, the oval-shaped objects in the inset photos.
The "curtains" of auroral light extend several hundred miles above the edge of Jupiter. Images of Earth's auroral curtains, taken from the space shuttle, have a similar appearance. Jupiter's auroras are viewed against a backdrop of the entire planet. The auroras are brilliant curtains of light in Jupiter's upper atmosphere. Jovian auroral storms, like Earth's, develop when electrically charged particles trapped in the magnetic field surrounding the planet spiral inward at high energies toward the north and south magnetic poles. When these particles hit the upper atmosphere, they excite atoms and molecules there, causing them to glow (the same process acting in street lights).
Here is the picture of Saturn taken by the Hubble telescope in ultraviolet light. The glowing, swirling material at Saturn's poles is its auroral "curtains," rising more than a thousand miles above the cloud tops.
Saturn's auroral displays are caused by an energetic wind from the Sun that sweeps over the planet, much like Earth's aurora, which is occasionally seen in the nighttime sky. The process that triggers these auroras is similar to the phenomenon that causes fluorescent lamps to glow.
Hubble Finds Most of Visible Light in the Universe
A closer look at the Hubble telescope's most detailed image, the Hubble Deep Field, reveals that the faint galaxies seen by Hubble could account for most of the visible light in the cosmos.
The Hubble Deep Field, an image obtained in 1995 when Hubble observed one location on the sky for two weeks, revealed galaxies that are billions of times fainter than could be seen with the naked eye. Astronomers probed apparently blank patches that lie between the faint galaxies, searching for tiny ripples in the sky brightness that would indicate the presence of even more galaxies. They found very little variation in brightness, indicating that most of the visible light filling the universe comes from galaxies like those in the Hubble Deep Field and not from still fainter galaxies.
Peering halfway across the universe to analyze light from exploded stars that died long before our Sun even existed, the Hubble telescope has allowed astronomers to determine that the expansion of the cosmos has not slowed since the initial impetus of the Big Bang. Thus, the universe's expansion should continue to balloon outward indefinitely.
These results are based on unprecedented distance measurements to supernovae that are so far away they allow astronomers to determine if the universe was expanding at a faster rate long ago. These images showcase three of the supernovae used in the survey. The arrows in the bottom row of pictures pinpoint these exploding stars; the top row of images shows the regions where the supernovae reside.
Astronomers Discover an Infrared Background Glow in the Universe
Astronomers have assembled the first definitive detection of a background infrared glow across the sky produced by dust warmed by all the stars that have existed since the beginning of time. For scientists, the discovery of this "fossil radiation" is akin to turning out all the lights in a bedroom only to find the walls, floor, and ceiling aglow with an eerie luminescence.
The telltale infrared radiation puts a limit on the total amount of energy released by all the stars in the universe. Astronomers say this will greatly improve development of models explaining how stars and galaxies were born and evolved after the Big Bang. These three pictures are maps of the full sky as seen in infrared light. The top picture represents the brightness of the full sky as seen in infrared light. The middle picture is a view of the sky after the foreground glow of the solar system dust has been extracted. After the infrared light from our solar system and galaxy has been removed, what remains is a uniform, cosmic, infrared background.
Teaming up space telescopes to make simultaneous ultraviolet and X-ray observations, astronomers may have solved a 20-year-old mystery and possibly discovered a new class of X-ray star.
The unlikely suspect is a second-magnitude star 600 light-years from Earth in the constellation Cassiopeia. It turns out that the mild-mannered-looking star is ejecting 100-million-degree flares into space - 10 times hotter than typical flares ejected from our Sun. The findings are based on observations by the Hubble telescope and the Rossi X-Ray Timing Explorer.
Space Telescope Science Institute Gets New Director
An agreement has been reached in principle to appoint Dr. Steven V. W. Beckwith director of the Space Telescope Science Institute (STScI), in Baltimore. The agreement is under negotiation and will be finalized in the near future. The appointment becomes effective on Sept. 1, 1998. Dr. Beckwith is currently the managing director of the Max-Planck Institute for Astronomy in Heidelberg, Germany.
The STScI carries out the scientific mission of the Hubble Space Telescope. The Association of Universities for Research in Astronomy, Inc., manages STScI for NASA. The European Space Agency participates in the Hubble Project under a long-term arrangement with NASA.
The Hubble telescope is giving astronomers a ringside seat to a never-before-seen titanic collision of an onrushing stellar shock wave with an eerie glowing gas ring encircling a nearby stellar explosion, called supernova 1987A.
Though the star's self-destruction was first seen nearly 11 years ago on Feb. 23, 1987, astronomers are just now beginning to witness its tidal wave of energy reaching the "shoreline" of the immense light-year-wide ring. Shocked by the 40-million-mile-per-hour sledgehammer blow, a 100-billion-mile-wide knot of gas in a piece of the ring has already begun to "light up," as its temperature surges from a few thousand degrees to a million degrees Fahrenheit. For comparison, the Hubble image on the left was taken before the collision. The picture on the right shows a glowing ball of gas [denoted by arrow].
Astronomers Track Down Asteroids in Hubble Archive
Astronomers have stumbled on an unusual asteroid hunting ground: the thousands of Hubble telescope images stored in the orbiting observatory's archive.
The hunt has yielded a sizable catch of small asteroids - about 100. A preliminary analysis suggests that a total population of 300,000 small asteroids - essentially rocks just over 1 to 3 kilometers wide (equal to half a mile to two miles) - are orbiting between Mars and Jupiter in a band of space debris known as the main belt. Currently, there are 8,319 confirmed main belt asteroids whose orbits have been measured, and about the same number have been sighted but not confirmed. These pictures are a sampling of what astronomers have found. The blue, curved lines mark an asteroid's trail.
The Hubble telescope continues to capture stunning, colorful snapshots of stellar burnout. These images reveal the beauty and complexity of planetary nebulae, the glowing relics of Sun-like stars.
This image of NGC 7027, for example, is one of the first infrared views of planetary nebulae taken with Hubble's infrared camera. In this picture, Hubble peers through the dusty core of a young planetary nebula to reveal the bright, central star. This picture also captures a young planetary nebula in a state of rapid transition.
The Hubble telescope has captured a flurry of star birth near the heart of the barred spiral galaxy NGC 1808.
This is a close-up view of the galaxy's center, the hotbed of vigorous star formation. The yellow color pinpoints older stars; the blue color reveals areas of star birth. NGC 1808 is called a barred spiral galaxy because of the straight lines of star formation on both sides of the bright nucleus. The bar may be the catalyst for this intense star formation. The rotation of the bar may have triggered the star birth, or matter streaming along the bar towards the central region may be feeding the stellar breeding ground.
The Hubble telescope has probed the inner regions of Comet Hyakutake. This picture captures sunlight scattered by dust particles in the comet's inner coma.
The coma is the head or dusty-gas atmosphere surrounding a comet's icy nucleus. This image will help astronomers understand the effects of sunlight on the comet's icy central region.
Hubble Reveals Details of a Newly Born Planetary Nebula
Astronomers have caught a peek at a rare moment in the final stages of a star's life: a ballooning shroud of gas cast off by a dying star flicking on its stellar light bulb. The Hubble telescope has captured the unveiling of the Stingray nebula (Hen-1357), the youngest known planetary nebula.
Twenty years ago, the nebulous gas entombing the dying star wasn't hot enough to glow. The Stingray nebula (Hen-1357) is so named because its shape resembles a stingray fish. Images of a planetary nebula in its formative years can yield new insights into the last gasps of ordinary stars like our Sun.
Hubble Finds That Even Massive Stars Just Fade Away
Pinpointing the rapidly fading ember of a recently burned-out star, the Hubble telescope is giving astronomers a better estimate on just how big a star can be before it ultimately explodes as a supernova.
Based on Hubble's detection of a rare, young white dwarf star, astronomers conclude that its progenitor was a whopping 7.6 times the mass of our Sun. Previously, astronomers had estimated that stars anywhere from 6 to 10 solar masses would not just quietly fade away as white dwarfs, but abruptly self-destruct in torrential explosions. In this picture, Hubble can easily resolve the star [the white circle] in the crowded cluster and detect its intense blue-white glow from a sizzling surface temperature of 50,000 degrees Fahrenheit.
Hubble Space Telescope Completes Eighth Year Of Exploration
In honor of NASA Hubble Space Telescope's eighth anniversary, we have gift-wrapped Saturn in vivid colors. Actually, this image is courtesy of Hubble's infrared camera, which has taken its first peek at Saturn.
This view provides detailed information on the clouds and hazes in Saturn's atmosphere. The blue colors indicate a clear atmosphere down to the main cloud layer. Most of the Northern Hemisphere that is visible above the rings is relatively clear. The dark region around the South Pole indicates a big hole in the main cloud layer. The green and yellow colors indicate a haze above the main cloud layer. The red and orange colors indicate clouds reaching up high into the atmosphere. The rings, made up of chunks of ice, are as white as images taken in visible light.
Gamma-Ray Burst Found to be Most Energetic Event in Universe
A team of astronomers has announced that a recently detected gamma-ray burst was as bright as the rest of the universe, releasing a hundred times more energy than previously theorized.
The team measured the distance to a faint galaxy from which the burst, designated GRB 971214, originated. It is about 12 billion light-years from Earth. The astronomers used a suite of satellites and ground-based telescopes to follow the burst. This Hubble image of the GRB 971214 field was taken about four months after the burst, well after the afterglow had faded away. The extremely faint and distant object marked with an arrow is the host galaxy of the gamma-ray burst.
