Dusty veil hides gargantuan sun
Br John Hoyland, Editor of New Scientist
THERE is a monstrous star, perhaps 40 million times as bright as the
sun, near the middle of our galaxy. It is the most luminous star ever
discovered.
Steve Eikenberry, of the University of Florida at Gainesville, and his
colleagues announced the discovery last week at a meeting of the
American Astronomical Society in Atlanta, Georgia. The star, called LBV
1806-20, had been spotted before, but interstellar dust clouds obscured
its true brilliance until Eikenberry and his team pinned down the star's
distance and temperature, as well as how much of its light is being
absorbed. Using data from several telescopes, they worked out that the
star behind the veil of dust is between 5 and 40 million times as
luminous as the sun.
That means it must be at least 150 times the sun's mass - impossibly
big, according to standard theory. Before it reached this mass, the
growing star should have got so bright that its radiation would have
blown away any surrounding gas, stopping its growth short. But LBV
1806-20 has other overweight companions. "It's an entire cluster of
freakishly massive stars," says Eikenberry.
The answer may lie nearby. A rare kind of neutron star just a few light
years from LBV 1806-20 is the remnant of a supernova explosion that went
off 1 or 2 million years ago. Shock waves from this explosion may have
squeezed gas in the surrounding nebula so violently that the young star
couldn't blow it away.
From NewScientist
http://www.newscientist.com/
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Posted by
Robert Karl Stonjek.
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