Credit: Pete Challis (CfA)
Astronomers have discovered Supernova 1987A, in the Large Magellanic Cloud,is getting brighter again.
(PhysOrg.com) -- In 1987, light from an exploding star in a neighboring galaxy, the Large Magellanic Cloud, reached Earth. Named Supernova 1987A, it was the closest supernova explosion witnessed in almost 400 years, allowing astronomers to study it in unprecedented detail as it evolves.
Today a team of astronomers announced that the supernova debris, which has faded over the years, is brightening. This shows that a different power source has begun to light the debris, and marks 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).
Kirshner leads a long-term study of SN 1987A with NASA's Hubble Space Telescope. Since its launch in 1990, Hubble has provided a continuous record of the changes in SN 1987A.
As shown in the accompanying image, SN 1987A is surrounded by a ring of material that blew off the progenitor star thousands of years before it exploded. The ring is about one light-year (6 trillion miles) across. Inside that ring, the "guts" of the star are rushing outward in an expanding debris cloud.
Most of a supernova's light comes from radioactive decay of elements created in the explosion. As a result, it fades over time. However, the debris from SN 1987A has begun to brighten, suggesting that a new power source is lighting it.