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NOTE TO EDITORSJune 20, 1997
BOOMERANG NEBULA BOASTS THE COOLEST SPOT IN THE UNIVERSE
Dr. Raghvendra Sahai of NASA's Jet Propulsion Laboratory,
Pasadena, CA, is available for interviews about the new discovery
of the coldest region in the universe. The cold region, found
some 5,000 light years from Earth in the Boomerang Nebula, has a
temperature of about 1 Kelvin, or minus 458 degrees Fahrenheit.
It represents the outer regions of a cold wind being blown by a
"The Boomerang is a cloud of dust and gas being spewed out
from an old star while its core collapses inward and becomes a
white dwarf, a star which has used up its nuclear fuel,"
according to Sahai, who co-discovered the cold region. "The
Boomerang Nebula is like a cosmic refrigerator, in which
expanding gas cools very efficiently down to the very chilly
temperatures we have found."
Sahai, had predicted the existence of such cold regions in a
paper published in the Astrophysical Journal in 1990. He made
the discovery along with Lars-Ake Nyman of the European Southern
Observatory and Onsala Space Observatory, Sweden, after several
observations between August and October of 1995. The work was
done on a radio telescope at La Silla, Chile, by comparing
signals received from carbon monoxide in the Boomerang Nebula
with signals from cosmic microwave background radiation which
pervades the whole universe. They discovered the cold region was
absorbing some of that background radiation. The results have
been submitted to Astrophysical Journal Letters.
Sahai believes the Boomerang Nebula is even colder than most
other expanding nebulae because it is losing its mass about 100
times faster than other similar dying stars and 100 billion times
faster than Earth's Sun. The nebula's dying star may represent
our Sun's fate in 10 billion years, when it exhausts its nuclear
fuel and becomes a white dwarf.
"Dying stars, like the one which produced the Boomerang
Nebula, play a vital role in creating solar systems like ours,"
said Sahai. As these stars die, they synthesize and scatter
elements like carbon and nitrogen and dust particles which sow
the seeds for the birth of new suns, planets and life."
[Note to Editors: A still image of the Boomerang Nebula is
available by calling the JPL Public Information Office.]