Tuesday, August 04, 2009

Pushing Back Time

Credit: X-ray: NASA/CXC/PSU/S.Park & D.Burrows.; Optical: NASA/STScI/CfA/P.Challis

February 24, 2007 marks the 20th anniversary of one of the most spectacular events observed by astronomers in modern times, Supernova 1987A. The destruction of a massive star in the Large Magellanic Cloud, a nearby galaxy, spawned detailed observations by many different telescopes, including NASA's Chandra X-ray Observatory and Hubble Space Telescope. The outburst was visible to the naked eye, and is the brightest known supernova in almost 400 years.

This composite image shows the effects of a powerful shock wave moving away from the explosion. Bright spots of X-ray and optical emission arise where the shock collides with structures in the surrounding gas. These structures were carved out by the wind from the destroyed star. Hot-spots in the Hubble image (pink-white) now encircle Supernova 1987A like a necklace of incandescent diamonds. The Chandra data (blue-purple) reveals multimillion-degree gas at the location of the optical hot-spots. These data give valuable insight into the behavior of the doomed star in the years before it exploded.
See:Supernova 1987A:
Twenty Years Since a Spectacular Explosion
(Bold added by me for emphasis)

Supernova Starting Gun: Neutrinos

Next they independently estimated how the hypothetical neutrinos would be picked up in a detector as massive as Super-Kamiokande in Japan, which contains 50,000 tons of water. The detector would only see a small fraction of the neutrinos. So the team outlined a method for matching the observed neutrinos to the supernova's expected luminosity curve to figure out the moment in time--to within about 10 milliseconds--when the sputtering star would have begun emitting neutrinos. In their supernova model, the bounce, the time of the first gravitational waves, occurs about 5 milliseconds before neutrino emission. So looking back at their data, gravitational wave hunters should focus on that point in time.
(again bold added for emphasis)


See Also:SciDAC Computational Astrophysics Consortium

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