Hubble Identifies a Long-Sought Population of Comets Beyond Neptune
The Hubble telescope has detected a long-sought population of comets dwelling at the icy fringe of the solar system. The observation, which is the astronomical equivalent to finding the proverbial needle-in-a-haystack, bolsters proof for a primordial comet reservoir just beyond Neptune. The circles pinpoint one of the candidate Kuiper belt objects. The dotted lines represent a possible orbit that this Kuiper belt comet is following.
Based on the Hubble observations, a team of astronomers estimate that the belt contains at least 200 million comets, which have remained essentially unchanged since the birth of the solar system 4.5 billion years ago.
Hubble Sheds Light on the "Faint Blue Galaxy" Mystery
Astronomers using the Hubble telescope have solved a 20-year-old mystery by showing that a class of galaxies once thought to be rare is actually the most common type of galaxy in the universe.
Analyzing some of the deepest images ever taken of the heavens, the astronomers conclude that small irregular objects called "blue dwarfs" were more numerous several billion years ago, outnumbering giant elliptical galaxies and spiral galaxies like our Milky Way. This means that blue dwarfs are a more important constituent of the universe and figure more prominently in the evolution of galaxies than previously thought.
Eerie, dramatic pictures from the Hubble telescope show newborn stars emerging from "eggs" – not the barnyard variety – but rather, dense, compact pockets of interstellar gas called evaporating gaseous globules (EGGs). Hubble found the "EGGs," appropriately enough, in the Eagle nebula, a nearby star-forming region 7,000 light-years from Earth in the constellation Serpens.
These striking pictures resolve the EGGs at the tip of finger-like features protruding from monstrous columns of cold gas and dust in the Eagle Nebula (also called M16). The columns – dubbed "elephant trunks" – protrude from the wall of a vast cloud of molecular hydrogen, like stalagmites rising above the floor of a cavern. Inside the gaseous towers, which are light-years long, the interstellar gas is dense enough to collapse under its own weight, forming young stars that continue to grow as they accumulate more and more mass from their surroundings.
Hubble's Deepest View of the Universe Unveils Bewildering Galaxies across Billions of Years
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 stages of evolution.
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.
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.
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.
Hubble Astronomers Unveil "Crab Nebula - The Movie"
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. Surrounding the pulsar is a complex of sharp knots and wisp-like features.
Hubble Sees Early Building Blocks of Today's Galaxies
New Hubble telescope images unveil what may be galaxies under construction in the early universe.
Hubble's detailed pictures reveal a grouping of 18 gigantic star clusters that appear to be the same distance from Earth, and close enough to each other that they will eventually merge into a few galaxy- sized objects. They are so far away, 11 billion light-years, that they existed during the epoch when it is commonly believed galaxies started to form. These results add weight to a leading theory that galaxies grew by starting out as clumps of stars, which, through a complex series of encounters, consolidated into larger assemblages that we see as fully formed galaxies.
Dramatic Hubble telescope pictures reveal that quasars live in a remarkable assortment of galaxies, many of which are violently colliding. This complicated picture suggests there may be a variety of mechanisms – some quite subtle – for "turning on" quasars, the universe's most energetic objects.
When seen through ground-based telescopes, these compact, enigmatic light sources resemble stars, yet they are billions of light-years away and several hundred billion times brighter than normal stars. The following Hubble snapshots offer examples of quasar home sites. Astronomers believe that a quasar turns on when a massive black hole at the center of a galaxy feeds on gas and stars.
The Egg Nebula, also known as CRL 2688, is shown on the left as it appears in visible light and on the right as it looks in infrared light. Both Hubble views recount the last gasps of a dying, Sun-like star.
Objects like the Egg Nebula are helping astronomers understand how stars like our Sun expel carbon and nitrogen ? elements crucial for life ? into space. Studies on the Egg Nebula show that these dying stars eject matter at high speeds along a preferred axis and may even have multiple jet-like outflows. The signature of the collision between this fast-moving material and the slower, out-flowing shells is the glow of hydrogen molecules [the red material] captured in the right-hand image.
The colorful "zigzag" on the right is not the work of a flamboyant artist, but the signature of a super-massive black hole in the center of galaxy M84, discovered by the Hubble telescope's imaging spectrograph.
The image on the left, also taken by Hubble, shows the core of the galaxy where the suspected black hole dwells. In a single exposure, astronomers mapped the motions of gas in the grip of the black hole's powerful gravitational pull by aligning Hubble's spectroscopic slit across the nucleus.
The Hubble telescope's infrared vision is providing a dramatic new look at the beautiful Orion Nebula, which contains the nearest nursery for massive stars.
For comparison, Hubble's visible-light view of the nebula is on the left. The heart of the giant Orion molecular cloud, OMC-1, is included in the relatively dim and featureless area inside the blue outline near the top of the image. Light from a few foreground stars provides only a hint of the many other stars embedded in this dense cloud. Hubble's infrared camera reveals a chaotic, active star birth region [as seen in the right-hand picture]. Here, stars and glowing interstellar dust, heated by and scattering the intense starlight, appear yellow-orange.
Hubble Chemically Analyzes the Ring around Supernova 1987A
These pictures from the Hubble telescope's imaging spectrograph provide a new and unprecedented look at one of the most unique and complex structures in the universe – a light-year-wide ring of glowing gas around supernova 1987A, the nearest stellar explosion in 400 years
The long-slit spectrograph viewed the entire ring system, dissecting its light and producing a detailed image of the ring in each of its component colors [the colorful loops on the right]. Each color represents light from specific elements in the ring's gases, including oxygen [single green ring], nitrogen and hydrogen [triple-orange rings], and sulfur [double-red rings]. By dismantling the ring into its different puzzle pieces – its component elements – astronomers hope to put together a picture of how the ring was created. The picture on the left is a view of the entire supernova.
Hubble Finds Cloudy, Cold Weather Conditions for Mars-Bound Spacecraft
As two NASA spacecraft speed toward a mid-year rendezvous with Mars, astronomers using the Hubble telescope are providing updated planetary weather reports to help plan the missions.
Hubble's new images show that the "Martian invasion" of spacecraft will experience considerably different weather conditions than seen by the last U.S. spacecraft to land on Mars 21 years ago. Martian atmospheric conditions will affect the operation of both the Mars Pathfinder landing on July 4, 1997 and the September 11 arrival of the Mars Global Surveyor, which will map the planet from orbit. These two Hubble snapshots were taken barely three weeks after another Hubble observations of the Red Planet. The differences in the two sets of images are striking, revealing dramatic changes in some local conditions and show overall cloudier and colder conditions than the Viking orbiter encountered two decades ago.
The Hubble telescope's infrared camera has peered into the Cone Nebula, revealing a stunning picture of six babies, Sun-like stars surrounding their mother, a bright, massive star. Known as NGC 2264 IRS, the massive star triggered the creation of these baby stars by releasing high-speed particles of dust and gas during its formative years.
The image on the left, taken in visible light by a terrestrial telescope, shows the Cone Nebula, located 2,500 light-years away in the constellation Monoceros. The white box pinpoints the location of the star nursery, which cannot be seen in this image because dust and gas obscure it. The infrared image on the right shows the massive star ? the brightest source in the region ? and the stars formed by its outflow.
The Hubble telescope's infrared camera has uncovered a collision between two spiral galaxies in the heart of the peculiar galaxy called Arp 220. The collision has provided the spark for a burst of star formation.
Hubble's infrared vision has captured bright knots of stars forming in the heart of Arp 220. The bright, crescent, moon-shaped object is a remnant core of one of the colliding galaxies. The core is a cluster of 1 billion stars. The core's half-moon shape suggests that its bottom half is obscured by a disk of dust about 300 light-years across. This disk is embedded in the core and may be swirling around a black hole. The core of the other colliding galaxy is the bright round object to the left of the crescent, moon-shaped object. Both cores are about 1,200 light-years apart and are orbiting each other.
Fireworks Near a Black Hole in the Core of Seyfert Galaxy NGC 4151
The Hubble telescope's imaging spectrograph simultaneously records, in unprecedented detail, the velocities of hundreds of gas knots streaming at hundreds of thousands of miles per hour from the nucleus of NGC 4151, thought to house a super-massive black hole. This is the first time the velocity structure in the heart of this object, or similar objects, has been mapped so vividly this close to its central black hole.
The heart of NGC 4151 was captured in visible light in the upper left picture. In the other images, Hubble's imaging spectrograph has zeroed in on the galaxy's active central region. The Hubble data clearly show that the some material in the galaxy's hub is rapidly moving towards us, while other matter rapidly receding from us. This information is strong evidence for the existence of a black hole, an extremely compact, dense object that feeds on material swirling around it.
Hubble Reveals Invisible High-Speed Collision around Supernova 1987A
The highest velocity material expelled in a cataclysmic, stellar explosion 10 years ago has been detected for the first time by the Hubble telescope's imaging spectrograph.
The top image, taken with Hubble's visible-light camera, shows the orange-red rings surrounding Supernova 1987A in the Large Magellanic Cloud. The glowing debris of the supernova explosion, which occurred in February 1987, is at the center of the inner ring. The small, white square indicates the location of the imaging spectrograph aperture. The Hubble data in the middle panel [and a schematic representation in the bottom panel] shows the presence of glowing hydrogen expanding at a speed of 33 million mph (15,000 kilometers per second) coming from an extended area inside the inner ring.
Hubble Identifies What May Be the Most Luminous Star Known
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.
