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Weird Object May Be Result Of Colliding Protoplanets
by Staff Writers
Austin TX (SPX) Jan 11, 2008
Something bizarre orbiting a young, failed star 170 light-years from Earth may be the progeny of two protoplanets that collided and merged, astronomers announced at the American Astronomical Society meeting in Austin, Texas, today. Given its hotter-than-expected temperature, dim luminosity, young age and location, the orbiting object, known as 2M1207B, should be a physical impossibility, scientists say.
"This is a strange enough object that it needs a strange explanation," Eric Mamajek of the Harvard-Smithsonian Center for Astrophysics said.
"Most, if not all, planets in our solar system were hit early in their history," Mamajek said. "A collision created Earth's moon and knocked Uranus on its side. It's quite likely that major collisions happen in other young planetary systems, too."
A Young Extrasolar Planet In Its Cosmic Nursery
by Staff Writers
Heidelberg, Germany (SPX) Jan 04, 2008
Scientists at the Max Planck Institute for Astronomy in Heidelberg have discovered the youngest known extrasolar planet. Its host star is still surrounded by the disk of gas and dust from which it was only recently born. This discovery allows scientists to draw important conclusions about the timing of planet formation.
How do planetary systems form? How common are they? What is their architecture? How many habitable earth-like planets exist in the Milky Way? In the past decade, astronomers have clearly come closer to finding answers to these exciting questions. With the discovery of the first planet orbiting another Sun-like star in 1995, the field of extrasolar planet research was born.
Unusual Supernovae May Reveal Intermediate-Mass Black Holes In Globular Clusters
by Tim Stephens
Santa Cruz CA (SPX) Jan 30, 2008
A strange and violent fate awaits a white dwarf star that wanders too close to a moderately massive black hole. According to a new study, the black hole's gravitational pull on the white dwarf would cause tidal forces sufficient to disrupt the stellar remnant and reignite nuclear burning in it, giving rise to a supernova explosion with an unusual appearance. Observations of such supernovae could confirm the existence of intermediate-mass black holes, currently the subject of much debate among astronomers.
This series of images shows the interaction of a white dwarf star with a black hole. As it passes the black hole, the white dwarf becomes strongly compressed and heated (bottom left), triggering an explosion. Most of the stellar mass is ejected into space (the "bubble" in the upper right part of the debris in the top left image), while the rest (the cusp-like part of the image) falls toward the black hole. While the ejected matter expands rapidly, the infalling matter builds a violent, thick accretion disk around the black hole.
The Growing-Up Of A Star
by Staff Writers
Paris, France (SPX) Jan 31, 2008
Using ESO's Very Large Telescope Interferometer, astronomers have probed the inner parts of the disc of material surrounding a young stellar object, witnessing how it gains its mass before becoming an adult. The astronomers had a close look at the object known as MWC 147, lying about 2,600 light years away towards the constellation of Monoceros ('the Unicorn').
MWC 147 belongs to the family of Herbig Ae/Be objects. These have a few times the mass of our Sun and are still forming, increasing in mass by swallowing material present in a surrounding disc.
MWC 147 is less than half a million years old. If one associated the middle-aged, 4.6 billion year old Sun with a person in his early forties, MWC 147 would be a 1-day-old baby.
Cosmic Suburbia Is A Better Breeding Ground For Stars
by Staff Writers
Pasadena CA (JPL) Jan 29, 2008
New observations from NASA's Spitzer Space Telescope suggest that galaxies prefer to raise stars in cosmic suburbia rather than in "big cities." Galaxies across the universe reside in cosmic communities, big and small. Large, densely populated galactic communities are called galaxy clusters. Like big cities on Earth, galaxy clusters are scattered throughout the universe, connected by a web of dusty "highways" called filaments.
While thousands of galaxies live within the limits of a cluster, smaller galactic communities are sprinkled along filaments, creating celestial suburbs. Over time, astronomers suspect that all galactic suburbanites will make their way to a cluster by way of filaments.
The blue dots are active star-forming galaxies in and around a galaxy cluster called Abel 1763. Observations from NASA's Spitzer Space Telescope show that galaxies in filaments form stars at twice the rate of galaxies in dense clusters. Image credit: NASA/JPL-Caltech
by mayufuru
| 2008-01-31 16:57