Astronomy and Stars
Discussions about astronomy and stars. As we look further out what can we find in the universe beyond Earth's atmosphere?
2,186 topics in this forum
-
- 0 replies
- 677 views
The Hubble telescope has been used successfully to measure the diameters of a special class of pulsating star called a Mira variable, which rhythmically change size. The results suggest these gigantic, old stars aren't round but egg-shaped. Knowing more about these enigmatic stars is crucial to understanding how stars evolve, and may preview the fate of our Sun, five billion years from now. Due to their distance, the stars are too small for their disks to be resolved in conventional visible-light pictures, so astronomers used Hubble's Fine Guidance Sensors to measure the widths of two Mira variables, R Leonis and W. Hydrae. View the full article
Last reply by HubbleSite, -
- 0 replies
- 658 views
Astronomers analyzing the Hubble Deep Field - the faintest view of the universe taken with the Hubble telescope - may have identified what may prove to be the most distant objects observed to date. Scattered among the nearly 2,000 galaxies in the Hubble images, which were taken in December 1995, researchers have found several dozen galaxies they believe exhibit characteristics which make them appear to be more distant than any seen previously. Six of the galaxies appear to be more distant than the farthest quasars, the current distance record holders. The arrow pinpoints one of those six galaxies. View the full article
Last reply by HubbleSite, -
- 0 replies
- 626 views
A huge, billowing pair of gas and dust clouds is captured in this stunning Hubble telescope picture of the super-massive star Eta Carinae. Even though Eta Carinae is more than 8,000 light-years away, features 10 billion miles across (about the diameter of our solar system) can be distinguished. Eta Carinae suffered a giant outburst about 150 years ago, when it became one of the brightest stars in the southern sky. Though the star released as much visible light as a supernova explosion, it survived the outburst. Somehow, the explosion produced two lobes and a large, thin equatorial disk, all moving outward at about 1.5 million miles per hour. Estimated to be 100 times he…
Last reply by HubbleSite, -
- 0 replies
- 728 views
Probing the mysterious heart of the Crab Nebula, the tattered remains of an exploding star, astronomers have found this object to be even more dynamic than previously understood. These findings are based on a cosmic "movie" assembled from a series of Hubble telescope observations. The sequence of pictures is giving astronomers a remarkable look at the dynamic relationship between the tiny Crab pulsar - the collapsed core of the exploding star - and the vast nebula of dust and gas that it powers. This picture, which reveals the inner parts of the Crab, represents one frame from the movie. The Crab pulsar is the star on the left [white dot] near the center of the frame. S…
Last reply by HubbleSite, -
- 0 replies
- 694 views
Using the Hubble telescope, two international teams of astronomers are reporting major progress in converging on an accurate measurement of the universe's rate of expansion - a value that has been debated for over half a century. These new results yield ranges for the age of the universe from 9-12 billion years and 11-14 billion years, respectively. The black and white photograph from a ground-based telescope shows the entire galaxy. The color image from the Hubble telescope shows a region in NGC 1365, a barred spiral galaxy located in a cluster of galaxies called Fornax. A barred spiral galaxy is characterized by a "bar" of stars, dust, and gas across its center. Astro…
Last reply by HubbleSite, -
The Space Telescope Science Institute (STScI) and the Astronomical Society of the Pacific (ASP) are pleased to announce the availability of RealSky CD, the digitized Palomar Observatory Sky Survey compressed by a factor of 100x, available on 8 CD-ROMs. View the full article
Last reply by HubbleSite, -
- 0 replies
- 674 views
This is a rare view of Saturn's rings seen just after the Sun has set below the ring plane. This perspective is unusual because the Earth is slightly above Saturn's rings and the Sun is below them. Normally we see the rings fully illuminated by the Sun. The Hubble telescope photograph reveals three bright ring features [moving from the outer to the inner rings]: the F Ring, the Cassini Division, and the C Ring. The low concentration of material in these rings allows light from the Sun to shine through them. The A and B rings are much denser, which limits the amount of light that penetrates through them. Instead, they are faintly visible because they reflect light from S…
Last reply by HubbleSite, -
- 0 replies
- 628 views
A new golden era of space exploration and discovery began April 24, 1990 with the launch and deployment of the Hubble telescope. Over the past six years Hubble's rapid-fire rate of unprecedented discoveries has invigorated astronomy. Not since the invention of the telescope nearly 400 years ago have astronomers' vision of the universe been so revolutionized over such a short stretch of time. This picture, released to commemorate Hubble's sixth anniversary, shows several blue, loop-shaped objects that are actually multiple images of the same galaxy. The duplicate images were produced by a cosmic lens in space: the massive cluster of yellow elliptical and spiral galaxies …
Last reply by HubbleSite, -
- 0 replies
- 576 views
The Hubble telescope has captured a view of a globular cluster called G1, a large, bright ball of light in the center of the photograph. G1, also known as Mayall II, orbits the Andromeda galaxy (M31), the nearest major spiral galaxy to our Milky Way. Located 130,000 light-years from Andromeda's center, G1 is the brightest globular cluster in the Local Group of galaxies, containing at least 300,000 old stars. The Local Group consists of about 20 nearby galaxies, including the Milky Way. View the full article
Last reply by HubbleSite, -
- 0 replies
- 621 views
The Hubble telescope has peered deep into Uranus's atmosphere to see clear and hazy layers created by a mixture of gases. Using infrared filters, Hubble captured detailed features of three layers of the planet's atmosphere. Hubble's images are different from the ones taken by the Voyager 2 spacecraft, which flew by Uranus 10 years ago. Those images - not taken in infrared light - showed a greenish-blue disk with very little detail. The infrared image allows astronomers to probe the structure of the planet's atmosphere, which consists mostly of hydrogen with traces of methane. View the full article
Last reply by HubbleSite, -
- 0 replies
- 644 views
The Hubble telescope has captured snapshots of Saturn with its rings nearly edge-on to our view. In the top image, the rings are barely visible. Saturn's largest moon, Titan, is casting a shadow on the planet. Four moons - Mimas, Tethys, Janus, and Enceladus - are clustered around the edge of Saturn's rings on the right. Two other moons - Pandora and Prometheus - appear in front of the ring plane. The rings are casting a shadow on Saturn because the Sun was above the ring plane. The bottom snapshot captures the planet with its rings slightly tilted. The moon Dione is on the lower right. The moon on Saturn's upper left is Tethys. View the full article
Last reply by HubbleSite, -
- 0 replies
- 591 views
The Hubble telescope has snapped a view of several generations of stars in the central region of the Whirlpool Galaxy (M51), located 23 million light-years from Earth in the constellation Canes Venatici (the Hunting Dogs). The spiral galaxy's massive center, the bright ball of light in the center of the photograph, is about 80 light-years across and has a brightness of about 100 million suns. Astronomers estimate that it is about 400 million years old and has a mass 40 million times larger than our Sun. The concentration of stars is about 5,000 times higher than in our solar neighborhood, the Milky Way Galaxy. View the full article
Last reply by HubbleSite, -
- 0 replies
- 669 views
The Space Telescope Science Institute (STScI) has selected nine young scientists for the 1996 Hubble Postdoctoral Fellowship Program. The awardees were selected from a pool of applications received from highly qualified candidates worldwide. Inaugurated in 1990, the Hubble Fellowship Program funds research opportunities for outstanding applicants selected from among the approximately 200 Ph.D. astronomers and astrophysicists who graduate annually. The program is a joint venture between NASA and STScI, in cooperation with astronomical institutions across the United States. View the full article
Last reply by HubbleSite, -
- 0 replies
- 601 views
Resembling a bizarre setting from a science fiction movie, dramatic images sent back by the Hubble telescope have surprised astronomers by uncovering thousands of gigantic, tadpole-shaped objects surrounding a dying star. Dubbed "cometary knots" because their glowing heads and gossamer tails superficially resemble comets, they are probably the result of a dying star's final outbursts. Though ground-based telescopic observations have hinted at such objects, they have not previously been seen in such abundance, say researchers. Hubble captured thousands of these knots from a doomed star in the Helix Nebula, the closest planetary nebula to Earth - 450 light-years away in t…
Last reply by HubbleSite, -
- 0 replies
- 649 views
The Hubble telescope snapped pictures of comet Hyakutake March 25, 1996, when the comet was just 9.3 million miles from Earth. Unlike most of the published images of Hyakutake, the Hubble pictures focus on a very small region near the heart of the comet, the icy, solid nucleus. The images provide an exceptionally clear view of the near-nucleus region of comet Hyakutake. The image above is a complete view of the 2,070-mile-wide (3,340-kilometer-wide) comet. This picture shows that most of the dust is being produced on the comet's sunward-facing hemisphere. Also at upper left are three small pieces that have broken off the comet and are forming their own tails. Vie…
Last reply by HubbleSite, -
- 0 replies
- 653 views
For the first time since Pluto's discovery 66 years ago, astronomers have at last directly seen details on the surface of the solar system's farthest known planet. The Hubble telescope's snapshots of nearly the entire surface of Pluto, taken as the planet rotated through a 6.4-day period, show that Pluto is a complex object, with more large-scale contrast than any planet, except Earth. Topographic features such as basins, or fresh impact craters may cause some of the variations across Pluto's surface. View the full article
Last reply by HubbleSite, -
- 0 replies
- 636 views
Hubble Space Telescope's ongoing black hole hunt has bagged yet another supermassive black hole in the universe. The compact object - equal to the mass of two billion suns - lies at the heart of the edge-on galaxy NGC 3115, located 30 million light-years away in the constellation Sextans. This result promises to open the way to systematic demographic studies of very massive black holes that might once have powered quasars - objects that are incredibly small, yet release a gusher of light and other radiation. View the full article
Last reply by HubbleSite, -
The planets Neptune and Pluto have been selected as targets for original observations by students who will soon be serving as Hubble Space Telescope (HST) "Co-Investigators", working alongside some of America's foremost astronomers. In Spring 1996, for the first time ever, students in grades K-12 will have a chance to help do real science using the HST. The Space Telescope Science Institute (STScI), which oversees Hubble's science program for NASA and the European Space Agency, contributed three HST orbits to the PASSPORT TO KNOWLEDGE educational project for this purpose. View the full article
Last reply by HubbleSite, -
- 0 replies
- 648 views
The Hubble telescope has provided strong evidence for the existence of a roughly Jupiter-sized planet orbiting the star Beta Pictoris. Detailed Hubble snapshots of the inner region of the 200-billion-mile-wide dust disk encircling the star reveal an unexpected warp. Researchers say the warp can be best explained as caused by the tug of an unseen planet. This is a visible-light image of the disk, which looks like a spindle because it is tilted nearly edge-on to our view. The bright star, which lies at the center of the disk, is blocked out in this image. View the full article
Last reply by HubbleSite, -
- 0 replies
- 571 views
This Hubble telescope picture of planetary nebula NGC 7027 reveals remarkable new details of the process by which a star like the Sun dies. The nebula is a glowing record of the star's final death throes. New features include faint, blue, concentric shells surrounding the nebula; an extensive network of red dust clouds throughout the bright inner region; and the hot, central white dwarf, visible as a white dot at the center. View the full article
Last reply by HubbleSite, -
- 0 replies
- 625 views
This Hubble telescope picture of the Egg Nebula, also known as CRL2688, shows a pair of mysterious "searchlight" beams emerging from a hidden star and criss-crossed by numerous bright arcs. This image sheds new light on the poorly understood ejection of stellar matter that accompanies the slow death of Sun-like stars. The nebula is really a large cloud of dust and gas ejected by the star, expanding at a speed of 115,000 mph (20 km/s). A dense cocoon of dust [the dark band in the center] enshrouds the star and hides it from our view. Starlight escapes more easily in directions where the cocoon is thinner and is reflected towards us by dust particles in the cloud, giving …
Last reply by HubbleSite, -
- 0 replies
- 662 views
This Hubble telescope snapshot of MyCn18, a young planetary nebula, reveals that the object has an hourglass shape with an intricate pattern of "etchings" in its walls. A planetary nebula is the glowing relic of a dying, Sun-like star. The results are of great interest because they shed new light on the poorly understood ejection of stellar matter that accompanies the slow death of Sun-like stars. According to one theory on the formation of planetary nebulae, the hourglass shape is produced by the expansion of a fast stellar wind within a slowly expanding cloud, which is denser near its equator than near its poles. View the full article
Last reply by HubbleSite, -
One peek into a small part of the sky, one giant leap back in time. The Hubble telescope has provided mankind's deepest, most detailed visible view of the universe. Representing a narrow "keyhole" view stretching to the visible horizon of the universe, the Hubble Deep Field image covers a speck of the sky only about the width of a dime 75 feet away. Though the field is a very small sample of the heavens, it is considered representative of the typical distribution of galaxies in space, because the universe, statistically, looks largely the same in all directions. Gazing into this small field, Hubble uncovered a bewildering assortment of at least 1,500galaxies at various …
Last reply by HubbleSite, -
- 0 replies
- 681 views
Confirming the presence of yet another super-massive black hole in the universe, astronomers using the Hubble telescope have found unexpected mysteries. The black hole and an 800-light-year-wide, spiral-shaped disk of dust fueling it are slightly offset from the center of the host galaxy, NGC 4261. Prior to Hubble observations, astronomers did not think dust was common in elliptical galaxies like NGC 4261, which were thought to have stopped making stars long ago due to the absence of the requisite raw materials: gas and dust. However, Hubble is showing that dust and dust disks are common in the centers of elliptical galaxies. View the full article
Last reply by HubbleSite, -
- 0 replies
- 618 views
The evidence consists of observations from 60-inch and 200-inch telescopes on Mount Palomar, and a confirmatory image from the Hubble telescope. The brown dwarf, called Gliese 229B (GL229B), is a small companion to the cool, red star Gliese 229, located 19 light-years from Earth in the constellation Lepus. Estimated to be 20 to 50 times the mass of Jupiter, GL229B is too massive and hot to be classified as a planet, but too small and cool to shine like a star. At least 100,000 times dimmer than Earth's Sun, the brown dwarf is the faintest object ever seen orbiting another star. View the full article
Last reply by HubbleSite,