Astronomers are concluding that monstrous black holes weren't simply born big but instead grew on a measured diet of gas and stars controlled by their host galaxies in the early formative years of the universe. These results, gleaned from a NASA Hubble Space Telescope census of more than 30 galaxies, are painting a broad picture of a galaxy's evolution and its long and intimate relationship with its central giant black hole. Though much more analysis remains, an initial look at Hubble evidence favors the idea that titanic black holes did not precede a galaxy's birth but instead co-evolved with the galaxy by trapping a surprisingly exact percentage of the mass of the central hub of stars and gas in a galaxy.
Streaming out from the center of the galaxy M87 like a cosmic searchlight is one of nature's most amazing phenomena, a black-hole-powered jet of electrons and other sub-atomic particles traveling at nearly the speed of light. In this Hubble telescope image, the blue jet contrasts with the yellow glow from the combined light of billions of unseen stars and the yellow, point-like clusters of stars that make up this galaxy. Lying at the center of M87, the monstrous black hole has swallowed up matter equal to 2 billion times our Sun's mass. M87 is 50 million light-years from Earth.
The Hubble telescope has snapped a view of a stellar demolition zone in our Milky Way Galaxy: a massive star, nearing the end of its life, tearing apart the shell of surrounding material it blew off 250,000 years ago with its strong stellar wind. The shell of material, dubbed the Crescent Nebula (NGC 6888), surrounds the "hefty," aging star WR 136, an extremely rare and short-lived class of super-hot star called a Wolf-Rayet. Hubble's multicolored picture reveals with unprecedented clarity that the shell of matter is a network of filaments and dense knots, all enshrouded in a thin "skin" of gas [seen in blue]. The whole structure looks like oatmeal trapped inside a balloon. The skin is glowing because it is being blasted by ultraviolet light from WR 136.
Lackluster comet LINEAR (C/1999 S4) unexpectedly threw astronomers a curve. Using the Hubble telescope, researchers were surprised to catch the icy comet in a brief, violent outburst when it blew off a piece of its crust, like a cork popping off a champagne bottle. The eruption, the comet's equivalent of a volcanic explosion (though temperatures are far below freezing, at about minus 100 degrees Fahrenheit in the icy regions of the nucleus or core), spewed a great deal of dust into space. This mist of dust reflected sunlight, dramatically increasing the comet's brightness over several hours. Hubble's sharp vision recorded the entire event and even snapped a picture of the chunk of material jettisoned from the nucleus and floating away along the comet's tail.
The globular cluster M15 is shown in this color image obtained with the Hubble telescope. Lying some 40,000 light-years from Earth in the constellation Pegasus, M15 is one of nearly 150 known globular clusters that form a vast halo surrounding our Milky Way galaxy. Each of these spherically shaped clusters contains hundreds of thousands of ancient stars. The stars in M15 and other globular clusters are estimated to be about 12 billion years old. They were among the first generations of stars to form in the Milky Way.
To the surprise and delight of astronomers, the Hubble telescope discovered a small armada of "mini-comets" left behind from what some scientists had prematurely thought was a total disintegration of the explosive Comet LINEAR. In one observation, Hubble's powerful vision has settled the fate of the mysteriously vanished solid nucleus of Comet LINEAR, which was reported "missing in action" following its passage around the Sun on July 26. Though comets have been known to break apart and vanish before, for the first time astronomers are getting a close-up view of the dismantling of a comet's nucleus due to warming by the Sun. The results support the popular theory that comet nuclei are really made up of a cluster of smaller icy bodies called "cometesimals."
Astronomers using NASA's Hubble Space Telescope have carried out the most complete inventory to date of brown dwarfs, one of the universe's most elusive types of objects, which dwell in limbo between stars and planets. The Hubble census provides new and compelling evidence that stars and planets form in different ways. Because the brown dwarfs "bridge the gap" between stars and planets, their properties reveal new and unique insights into how stars and planets form.
Hubble Spies Brown Dwarfs in Nearby Stellar Nursery
Probing deep within a neighborhood stellar nursery, NASA's Hubble Space Telescope uncovered a swarm of newborn brown dwarfs. The orbiting observatory's near-infrared camera revealed about 50 of these objects throughout the Orion Nebula's Trapezium cluster [image at right], about 1,500 light-years from Earth. Appearing like glistening precious stones surrounding a setting of sparkling diamonds, more than 300 fledgling stars and brown dwarfs surround the brightest, most massive stars [center of picture] in Hubble's view of the Trapezium cluster's central region. The brown dwarfs are too dim to be seen in an image taken by the Hubble telescope's visible-light camera [picture at left].
Astronomers using NASA's Hubble Space Telescope have stumbled upon a mysterious object that is grudgingly yielding clues to its identity. A quick glance at the Hubble picture at top shows that this celestial body, called He 2-90, looks like a young, dust-enshrouded star with narrow jets of material streaming from each side. But it's not. The object is classified as a planetary nebula, the glowing remains of a dying, lightweight star. But the Hubble observations suggest that it may not fit that classification, either. The Hubble astronomers now suspect that this enigmatic object may actually be a pair of aging stars masquerading as a single youngster. One member of the duo is a bloated red giant star shedding matter from its outer layers. This matter is then gravitationally captured in a rotating, pancake-shaped accretion disk around a compact partner, which is most likely a young white dwarf (the collapsed remnant of a sun-like star). The stars cannot be seen in the Hubble images because a lane of dust obscures them.
Glowing like a multi-faceted jewel, the planetary nebula IC 418 lies about 2,000 light-years from Earth in the constellation Lepus. In this picture, the Hubble telescope reveals some remarkable textures weaving through the nebula. Their origin, however, is still uncertain.
Centaur's Bright Surface Spot Could be Crater of Fresh Ice
The unexpectedly varied surface of a wayward piece of space debris has given astronomers new insights into the characteristics and behavior of a ghostly population of faintly observed comet-like bodies that lie just beyond Pluto's orbit. While observing an object called 8405 Asbolus, a 48-mile-wide (80-kilometer-wide) chunk of ice and dust that lies between Saturn and Uranus, astronomers using the Hubble telescope were surprised to find that one side of the object looks like it has a fresh crater less than 10 million years old, exposing underlying ice that is apparently unlike any yet seen. This shows that these mysterious objects, called Centaurs, do not have a simple homogenous surface. Hubble didn't directly see the crater - the object is too small and far away - but a measure of its surface composition with its near-infrared camera shows a complex chemistry.
Movies from Hubble Show the Changing Faces of Infant Stars
Time-lapse movies made from a series of pictures taken by NASA's Hubble Space Telescope are showing astronomers that young stars and their surroundings can change dramatically in just weeks or months. As with most children, a picture of these youngsters taken today won't look the same as one snapped a few months from now. The movies show jets of gas plowing into space at hundreds of thousands of miles per hour and moving shadows billions of miles in size. The young star systems featured in the movies, XZ Tauri and HH 30, reside about 450 light-years from Earth in the Taurus-Auriga molecular cloud, one of the nearest stellar nurseries to our planet. Both systems are probably less than a million years old, making them relative newborns, given that stars typically live for billions of years.
Hubble Peeks into a Stellar Nursery in a Nearby Galaxy
The Hubble telescope has peered deep into a neighboring galaxy to reveal details of the formation of new stars. Hubble's target was a newborn star cluster within the Small Magellanic Cloud, a small satellite galaxy of our Milky Way. The picture shows young, brilliant stars cradled within a nebula, or glowing cloud of gas, cataloged as N 81.
Astronomers Ponder Lack of Planets in Globular Cluster
Astronomers using the Hubble telescope made the first broad search for planets far beyond our local stellar neighborhood. They trained Hubble's "eagle eye" for eight days on a swarm of 35,000 stars in 47 Tucanae, located in the southern constellation Tucana. The researchers expected to find 17 "extrasolar" planets. To their surprise, they found none. These results may be the first evidence that conditions for planet formation and evolution are different in other regions of our Milky Way Galaxy.
What appears as a bird's head, leaning over to snatch up a tasty meal, is a striking example of a galaxy collision in NGC 6745. The "bird" is a large spiral galaxy, with its core still intact. It is peering at its "prey," a smaller passing galaxy (nearly out of the field of view at lower right). The bright blue beak and bright, whitish-blue top feathers show the distinct path taken during the smaller galaxy's journey. These galaxies did not merely interact gravitationally as they passed one another; they actually collided.
Hubble Sees Bare Neutron Star Streaking Across Space
It's as big as Manhattan Island, is 10 trillion times denser than steel, and is hurtling our way at speeds over 100 times faster than a supersonic jet. An alien spaceship? No, it's a runaway neutron star, called RX J185635-3754, forged in a stellar explosion that was visible to our ancestors in 1 million B.C. Precise observations made with the Hubble telescope confirm that the interstellar interloper is the closest neutron star ever seen. The object also doesn't have a companion star that would affect its appearance. Now located 200 light-years away in the southern constellation Corona Australis, it will swing by Earth at a safe distance of 170 light-years in about 300,000 years.
Hubble Captures an Extraordinary and Powerful Active Galaxy
The Hubble telescope has taken a snapshot of a nearby active galaxy known as Circinus. This active galaxy belongs to a class of mostly spiral galaxies called Seyferts, which have compact centers and are believed to contain massive black holes. Seyfert galaxies are themselves part of a larger class of objects called Active Galactic Nuclei or AGN. AGN have the ability to remove gas from the centers of their galaxies by blowing it out into space at phenomenal speeds. Astronomers studying the Circinus galaxy are seeing evidence of a powerful AGN at its center.
This ghostly apparition is actually an interstellar cloud caught in the process of destruction by strong radiation from a nearby hot star. This haunting picture, snapped by the Hubble telescope, shows a cloud illuminated by light from the bright star Merope. Located in the Pleiades star cluster, the cloud is called IC 349 or Barnard's Merope Nebula.
In this Hubble telescope picture, a curtain of glowing gas is wrapped around Jupiter's north pole like a lasso. This curtain of light, called an aurora, is produced when high-energy electrons race along the planet's magnetic field and into the upper atmosphere where they excite atmospheric gases, causing them to glow. The aurora resembles the same phenomenon that crowns Earth's polar regions. But this Hubble image, taken in ultraviolet light, also shows the glowing "footprints" of three of Jupiter's largest moons: Io, Ganymede, and Europa. Over the next two months, Jupiter's aurora will be scrutinized by two observatories: the Hubble telescope and the Cassini spacecraft, which will fly by the planet on its voyage to Saturn.
"X" Marks the Spot: Hubble Sees the Glow of Star Formation in a Neighbor Galaxy
The saying "X" marks the spot holds true in this Hubble telescope image. In this case, X marks the location of Hubble-X, a glowing gas cloud in one of the most active star-forming regions in galaxy NGC 6822. The galaxy lies 1.6 million light-years from Earth in the constellation Sagittarius, one of the Milky Way's closest neighbors. This hotbed of star birth is similar to the fertile regions in the Orion Nebula in our Milky Way Galaxy, but on a vastly greater scale. The intense star birth in Hubble-X occurred about 4 million years ago, a small fraction of the approximate 10-billion-year age of the universe.
