domingo, 12 de junio de 2011

Young Supernova Has Bright Future

This HST image of SN 1987A shows the brightening ring of supernova debris. The closest supernova explosion seen in almost 400 years, it is located in the Large Magellanic Cloud. Credit: Pete Challis (CfA)
Way back in 1987 we received a present from our neighboring galaxy, the Large Magellanic Cloud. It was an unprecedented event and the most exciting thing astronomers had seen in nearly four hundred years. It was a chance to study stellar evolution first-hand – with details allowed by modern equipment. Just what was it? The closest supernova explosion to date…
On June 8, 2011 a team of astronomers announced the supernova debris of SN 1987A, which has dimmed with time, is brightening again. The observations conclude a different power source is igniting the debris – beginning the transition from a supernova to a supernova remnant. “Supernova 1987A has become the youngest supernova remnant visible to us,” said Robert Kirshner of the Harvard-Smithsonian Center for Astrophysics (CfA) and leader of the long-term SN 1987A study with NASA’s Hubble Space Telescope.
Supernova remnants are made up of material ejected from the parent exploding star and interstellar matter picked up along the way. Long before the cataclysmic event, a ring of material is ejected – spreading out about one light-year (6 trillion miles) across. Inside the circle, the inner workings of the host star are rushing out to form the expanding debris cloud. It is lit by radioactive decay and brightening points towards a new power source. “It’s only possible to see this brightening because SN 1987A is so close and Hubble has such sharp vision,” Kirshner said.
What can we expect in SN1987A’s future? Right now it’s able to give us valuable information about the last few thousand years of a star’s life. By studying the unusual clumps and bumps in the ring’s structure, astronomers may be able to decode its history… History that will be lost as debris expansion wipes out the structure. “Young supernova remnants have personality,” Kirshner agreed.
For now, this young supernova is allowing us to take a look at a future so bright, it’s gotta’ wear shades.