WASHINGTON, Aug. 12 (UPI) — Astronomers say they’ve detected gamma rays from an exploding nova for the first time, a finding that overturns prevailing thought about such explosions.
A nova is a sudden, short-lived brightening when a white dwarf in a binary system erupts in an enormous thermonuclear explosion, but most scientists had believed such explosions were not powerful enough to emit high-energy gamma radiation, NASA said Thursday.
Gamma rays are the most energetic form of light, and NASA’s Fermi’s Large Area Telescope detected the nova for 15 days.
“In human terms, this was an immensely powerful eruption, equivalent to about 1,000 times the energy emitted by the sun every year,” Elizabeth Hays, a Fermi project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md., said.
The white dwarf is about 9,000 light-years away, part of a so-called symbiotic binary containing a compact white dwarf and a red giant star about 500 times the size of the sun. More powerful supernovae explosions were known to generate gamma rays, but it was not thought smaller novae explosion were capable of it, NASA said.
Supernovae remnants endure for 100,000 years and affect regions of space thousands of light-years across, scientists say. One scientist compared astronomical studies of supernova remnants to looking at static images in a photo album.
“It takes thousands of years for supernova remnants to evolve, but with this nova we’ve watched the same kinds of changes over just a few days,” Kent Wood of the Naval Research Laboratory in Washington said.
“We’ve gone from a photo album to a time-lapse movie.”
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