Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

April 7, 1997
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GRB970228: What's There?
J. van Paradijs (UAH) et al., HST, NASA

Explanation: Could this fuzzy blob be the key to the whole gamma-ray burst (GRB) mystery? Astronomers the world over are now scrambling to determine the true nature of the extended emission seen to the lower right of the bright source in the above image. The bright object in the center is rapidly fading - and thought to be the first true optical counterpart to a GRB. But is it housed in a galaxy? If so, after the central emission has faded, this galaxy should be identifiable. Today, follow up observations of this blob are planned with the Hubble Space Telescope. If the extended emission does come from a galaxy it would bolster indications that the February 28th GRB occurred in that galaxy, across the universe from us. This, in turn, would imply that GRBs are truly the most powerful explosions ever known.

Tomorrow's picture: Comet Hale-Bopp Over New York City

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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
&: Michigan Tech. U.