Black hole gulps remote star
Pastor Dale Morgan
Black hole gulps remote star*
POSTED: 1714 GMT (0114 HKT), December 6, 2006
WASHINGTON (Reuters) -- A giant black hole displaying horrifying table
manners has been caught in the act of guzzling a star in a galaxy 4
billion light-years away, scientists using an orbiting NASA telescope
said on Tuesday.
For the past two years, scientists have monitored the dramatic events as
the star, residing in a galaxy in the Bootes constellation, was ripped
apart by the black hole.
Scientists used NASA's Galaxy Evolution Explorer, an orbiting telescope
sensitive to two bands of ultraviolet wave lengths, to detect an
ultraviolet flare coming from the center of a remote elliptical galaxy.
"This ultraviolet flare was from a star literally being ripped apart and
swallowed by the black hole," Suvi Gezari of the California Institute of
Technology in Pasadena and lead author of the paper describing the
findings in Astrophysical Journal Letters, said in an interview.
"This is the first time that we've actually been able to monitor the
flare of radiation from such an event in detail. Only once every 10,000
years will a star pass close enough to a (galaxy's) central black hole
to be ripped apart and swallowed in this manner," Gezari said.
The scientists hope the findings will give them a better understanding
of black holes, objects whose gravity is so powerful even light cannot
escape.
It is believed that super-massive black holes are located at the core of
every galaxy. For example, Gezari said, the Milky Way galaxy in which
our solar system resides has a dormant super-massive black hole at its
center.
Scientists said in this case the unfortunate star strayed a bit too
close to the black hole deep inside the galaxy, and was mutilated by the
force of its gravity. They believe that parts of the star swirled around
and then plunged into the black hole, which sent out the bright
ultraviolet flare that the satellite detected.
Scientists continue to use the telescope to observe the ultraviolet
light as it fades while the black hole snacks on the final table scraps
from the devoured star.
"We looked at the galaxy in 2003 and there was no ultraviolet light
coming from the galaxy at all," Gezari said. "And then in 2004, we
suddenly saw this very bright source."
"The only way to explain such a luminous ultraviolet flare is if the
black hole swallowed a star," Gezari said.
Caltech leads the Galaxy Evolution Explorer mission and is responsible
for science operations and data analysis, while NASA's Jet Propulsion
Laboratory manages the mission and built the instrument.
The scientists also used data from NASA's Chandra X-ray Observatory, the
Canada France Hawaii Telescope in Hawaii and the Keck Telescope in Hawaii.