Thirteen years ago, astronomers witnessed the brightest stellar explosion seen from Earth since 1604. Now, they're seeing fireworks generated as material from that explosion rams into and heats up a ring of gas surrounding the exploding star.
The spectacle, 169,000 light-years away in a galaxy called the Large Magellanic Cloud, may shed light on the nature of the original explosion, a supernova known as 1987A, as well as on its surroundings.
The orbiting Hubble Space Telescope viewed the unfolding drama on Feb. 2. It recorded four bright knots of heated gas within the ring, which had been slowly fading for a decade. The knots are regions where the blast wave, rushing out at 64 million kilometers per hour from the supernova, has smacked into the ring, heating it to millions of kelvins. Researchers saw an early sign of such a collision in 1997, when a single knot in the ring began shining brightly (SN: 2/14/98, p. 100).
"That was the opening jab. Now, the dancing around is over, and the slugfest will begin," says Robert P. Kirshner of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. He and his colleagues reported the finding in a Feb. 7 circular of the International Astronomical Union.
Predicted since 1992, the fireworks are expected to set the entire ring aglow over the next decade. As the blast wave continues to travel outward and reveal previously unseen material, it will allow astronomers to map the distribution of gas around the supernova and may illuminate two mysterious outer rings.
Robert P. Kirshner
Harvard-Smithsonian Center for Astrophysics
60 Garden Street, MS-19
Cambridge, MA 02138
Cowen, R. 1998. Shock wave revives fading supernova ring. Science News 153(Feb. 14):100.