Supernova patrol make its first score.

Supernova patrol makes its first score

Supernovas are extremely transient astrophysical phenomena. Giant explosions of stars, they appear unpredictably in the sky and fade away in a few weeks at most. Astronomers probably miss many of them, and they tend to find the ones they do find late in their development. To remedy these deficiencies, a group of astrophysicists from the Lawrence Berkeley Laboratory (LBL) in Berkeley, Calif, has set up an automated sky patrol to search the sky in a regular pattern for incipient supernovas. On May 17 the patrol found its first supernova in the galaxy M99, a member of the Virgo cluster about 60 million light-years from us.

Frank Crawford, professor of physics at the University of California at Berkeley (UCB) and a member of the LBL team, found the supernova by comparing a picture made that morning with one of the same galaxy made May 9. Thus, he determined that the first light from the supernova must have reached the earth sometime between those two dates. The circumstance illustrates the principle of the patrol: It surveys about 1,000 galaxies, returning to each at intervals of about a week. When it is fully operational, the program should return to each galaxy every night, giving astronomers the best possible chance of getting supernovas at their very beginnings.

Supernovas are the final act in the lives of many stars. They are also the only plausible place for the synthesis of the heavier chemical elements. The explosions eject these elements, plus those made in previous stages of the star's life cycle, into space, where they are available for recycling into new generations of stars and planets. If the brightness and spectral characteristics of supernovas could be firmly determined, they could offer astrophysicists and cosmologists valuable markers for unambiguous determinations of the distances to the galaxies where they happen.

The system was several years in preparation (SN: 1/15/83, p. 44). It uses a 30-inch telescope at the University of California's Leuschner Observatory in Lafayette, located in the East Bay hills near Berkeley. Other members of the group are Richard Muller, Carl Pennypacker, Shane Burns, Peter Friedman, Jordin Kare, Saul Perlmutter, Craig Smith, R. Treffers, J. Graham and Roger Williams of LBL and UCB and V. Junkkainen of UC San Diego.