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Monday, March 14, 2011

Capturing the Most Violent Event in the Universe

Gamma ray burst from an exploding star. Image Source: ESA, Stephen Holland (Danish Centre for Astrophysics with the HST), Jens Hjorth, Johan Fynbo (University of Copenhagen) via Daily Galaxy.

Caption for the above phorograph: The image ... is an enlargement of a combined image obtained with the Space Telescope Imaging Spectrograph (STIS) onboard the NASA/ESA Hubble Space Telescope through a clear filter (shown in blue) and a red filter (shown in red). The region shows the star-formation taking place around the gamma-ray burst region in the galaxy ESO 184-G82.

Hubble telescope has captured the most violent event in the universe - a rare combination of a gamma ray burst with an exploding supernova.  From the Daily Galaxy:
In this new image from the Hubble Space Telescope, you'll see a spectacular gamma ray burst and supernova as a bright point in the irregular galaxy located approximately 820 million light years from the Earth. An international team of researchers made the discovery using NASA's Swift satellite.

"That we have observed a gamma ray burst and a supernova simultaneously is unusual and it gives us a long awaited confirmation of the theory that gamma ray bursts are indeed associated with exploding giant stars", explains Johan Fynbo, astrophysicist at the Dark Cosmology Center, Niels Bohr Institute at the University of Copenhagen. ...

"Only about one out of 10,000 supernovae produce gamma ray bursts, and gamma ray bursts in the relatively near universe are even more rare, so it gives us a unique opportunity to study the phenomena in detail. When you have one that is so near, it is like a clock telling you that the star is dying just NOW, and you can follow the early phases and the entire development of the supernova explosion that follows", explained Johan Fynbo.

It is only the very large, massive stars of more than 30-40 solar masses that produce gamma ray bursts. What happens is that when the star dies, it collapses and forms a black hole. If the black hole spins very quickly, a jet might appear - a gamma ray burst, which is powerful, high-energy radiation, which shoots out at nearly the speed of light. It happens very quickly and only lasts a few seconds.

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