Astronomy and Stars
Discussions about astronomy and stars. As we look further out what can we find in the universe beyond Earth's atmosphere?
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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. View the full article
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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; th…
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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…
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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 ener…
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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. View the full article
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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…
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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…
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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…
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Using the Hubble telescope's visible-light camera, astronomers for the first time this century have detected clouds in the Northern Hemisphere of Uranus. The snapshots show banded structure and multiple clouds. Using these images, astronomers plan to measure the wind speeds in the Northern Hemisphere for the first time. The clouds can be seen along the planet's right edge [the bright dots]. Another cloud [faint white dot] is barely visible near the bottom of the blue band. The clouds are almost as large as continents on Earth, such as Europe. View the full article
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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. View the full article
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Astronomers have long been mystified by observations of a few hot, bright, apparently young stars residing in well-established communities where most of their neighbors are much older. With the help of the Hubble telescope, astronomers now have evidence that may eventually help solve the 45-year-old mystery of how these enigmatic stars, called blue stragglers, were formed. For the first time, astronomers have confirmed that a blue straggler in the core of a globular cluster (a very dense community of stars) is a massive, rapidly rotating star that is spinning 75 times faster than the Sun. This finding provides proof that blue stragglers are created by collisions or othe…
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The Hubble telescope has uncovered over 1,000 bright; young star clusters bursting to life in a brief, intense, brilliant "fireworks show" at the heart of a pair of colliding galaxies. The picture on the left provides a sweeping view of the two galaxies, called the Antennae. The green shape pinpoints Hubble's view. Hubble's close-up view [right] provides a detailed look at the "fireworks" at the center of this wreck. The respective cores of the twin galaxies are the orange blobs, left and right of center, crisscrossed by filaments of dark dust. A wide band of chaotic dust stretches between the cores of the two galaxies. The sweeping spiral-like patterns, traced by brigh…
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Astronomers using the Hubble telescope have identified what may be the most luminous star known ? a celestial mammoth that releases up to 10 million times the power of the Sun and is big enough to fill the diameter of Earth's orbit. The star [center of image] unleashes as much energy in six seconds as our Sun does in one year. The image, taken in infrared light, also reveals a bright nebula [magenta-colored material], created by extremely massive stellar eruptions. The nebula is so big (4 light-years) that it would nearly span the distance from the Sun to Alpha Centauri, the nearest star to Earth's solar system. View the full article
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Astronomers using the Hubble telescope have taken their first direct look in visible light at a lone neutron star. This view offers a unique opportunity to pinpoint the star's size and to narrow theories about the composition and structure of this bizarre class of gravitationally collapsed, burned out stars. The Hubble results show that the star [marked by white arrow] is very hot and can be no larger than 16.8 miles (28 kilometers) across. These findings prove that the object must be a neutron star, for no other known type of object can be this hot, small, and dim. View the full article
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Nova eruptions by dying stars were thought to be simple, predictable acts of violence. Astronomers could point a telescope at the most recently exploded novae and see an expanding bubble of gaseous debris around each star. Scientists using the Hubble telescope, however, were surprised to find that some nova outbursts may not produce smooth shells of gas, but thousands of gaseous blobs, each the size of our solar system. In this Hubble picture of the nova T Pyxidis, the shells of gas ejected by the star are actually more than 2,000 gaseous blobs packed into an area that is 1 light-year across. View the full article
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This Hubble telescope picture of Mars was taken Sept. 12, 1997, one day after the arrival of the Mars Global Surveyor (MGS) spacecraft and only five hours before the beginning of autumn in the Martian Northern Hemisphere. This Hubble picture was taken in support of the MGS mission. Hubble is monitoring Martian weather conditions, such as large dust storms, during the early phases of the spacecraft's aerobraking. View the full article
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Hubble telescope observations of the ever-fading fireball from one of the universe's most mysterious phenomena ? a gamma-ray burst ? is reinforcing the emerging view that these titanic explosions happen far away in other galaxies and are among the most spectacularly energetic events in the universe. In this Hubble image of the gamma-ray burst's visible-light component, the fireball has faded to 1/500th its brightness since its discovery in March 1997 by ground-based telescopes. Hubble continues to clearly see the fireball [center of picture] and a cloud of material surrounding it, which is considered to be its host galaxy. View the full article
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Probing the heart of the active galaxy NGC 6251, the Hubble telescope has provided a never-before-seen view of a warped disk or ring of dust caught in a blazing torrent of ultraviolet light from a suspected massive black hole. This discovery suggests that the environments around black holes may be more varied than thought previously and may provide a new link in the evolution of black holes in the centers of galaxies. This composite picture of the galaxy's core of the galaxy combines visible- and ultraviolet-light observations. While the visible-light image shows a dark dust disk, the ultraviolet image [color-coded blue] reveals a bright feature along one side of the di…
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Astronomers have used the Hubble Space telescope to discover a giant impact crater on the asteroid Vesta. The crater is a link in a chain of events thought responsible for forming a distinctive class of tiny asteroids as well as some meteorites that have reached the Earth. The giant crater is 285 miles across, which is nearly equal to Vesta's 330-mile diameter. If Earth had a crater of proportional size, it would fill the Pacific Ocean basin. Astronomers had predicted the existence of one or more large craters, reasoning that if Vesta is the true "parent body" of some smaller asteroids then it should have the wound of a major impact that was catastrophic enough to knock…
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Although the giant star Mira has been known for about 400 years, astronomers have had to wait for the Hubble telescope to provide the first ultraviolet-light images of the extended atmosphere of the cool red giant star and its nearby, hot companion. By giving astronomers a clear view of the individual members of this system, Hubble has provided valuable insights into other types of double-star systems where the stars are so close they interact with one another. In ultraviolet light, Hubble resolves a small, hook-like appendage extending from Mira and pointing towards the smaller companion. This material could be gravitationally drawn towards Mira's mate. View the…
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An international team of astronomers has discovered the most distant galaxy in the universe to date. They found it by combining the unique sharpness of the Hubble telescope with the light-collecting power of the W. M. Keck Telescopes – with an added boost from a gravitational lens in space. The results show the young galaxy is as far as 13 billion light-years from Earth, based on an estimated age for the universe of approximately 14 billion years. The Hubble picture at left shows the young galaxy as a red crescent to the lower right of center. The galaxy's image is brightened, magnified, and smeared into this arc-shape by the gravitational influence of an intervening ga…
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Astronomers using the Hubble telescope to track weather on Mars and how it might affect the Pathfinder landing site in Ares Vallis report that a large dust storm seen south of the site only 12 days earlier has dissipated. However, a new dust storm has appeared in the polar region, about 1,200 miles (2,000 kilometers) due north of the landing site. The Hubble researchers conclude that Pathfinder landed during a period when large changes in the regional distributions of dust and clouds were taking place on Mars. The green cross on the bottom picture identifies the Pathfinder landing site. View the full article
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Hubble telescope pictures of Mars, taken June 27, 1997 in preparation for the July 4 landing of the Pathfinder spacecraft, show a dust storm churning through the deep canyons of Valles Marineris, just 600 miles (1,000 kilometers) south of the Pathfinder spacecraft landing site. Astronomers also report the presence of patchy cirrus clouds over the landing site and very thick clouds to the north. Because there are so many clouds (related to low temperatures in the atmosphere causing water vapor to freeze), the dust will probably stay confined to the canyons, they conclude. The green cross on the bottom picture identifies the Pathfinder landing site. View the full a…
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The Hubble telescope has snapped a picture of a 400-kilometer-high (250-mile-high) plume of gas and dust from a volcanic eruption on Io, Jupiter's large, innermost moon. Io was passing in front of Jupiter when Hubble took this image. The plume appears as an orange patch just off the edge of Io [at eight o'clock], against the blue background of Jupiter's clouds. Io's volcanic eruptions blast material hundreds of kilometers into space in giant plumes of gas and dust. In this image, material must have been blown out of the volcano at more than 2,000 mph to form a plume of this size, which is the largest yet seen on Io. View the full article
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Nature's most powerful explosions, gamma-ray bursts, occur among the normal stellar population inside galaxies scattered across the universe. The energy released in such a titanic explosion, which can last from a fraction of a second to a few hundred seconds, is equal to all of the Sun's energy generated over its 10-billion-year lifetime. Here is the visible glow from one such burst, GRB 970228. This Hubble telescope picture is the first visible-light view ever taken that links a gamma-ray burst with a potential host galaxy. This observation provides strong supporting evidence that gamma-ray bursts are cosmological- they originate in distant galaxies across the universe…
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