A Super Stargazer

If Las Vegas made book on which amateur astronomer would be the first to spot the next supernova, the odds-on favorite would have to be Robert Evans, 50, a Uniting Church minister from New South Wales, Australia. True, the skies were cloudy overhead on Feb. 23, and Evans missed the chance to be acclaimed the discoverer of spectacular 1987A. But four days later he was the first to sight the much dimmer, more distant 1987B, the year's second supernova. According to Brian Marsden of the International Astronomical Union, that was only the 18th visual discovery of a supernova by an amateur stargazer in this century. Yet 15 of those stellar explosions have been found by Evans, most of them on a homemade telescope and all since 1981.

By day Evans tends his flock in the rural parish of the Lower Blue Mountains. By night, sometimes all night, he scans the heavens with a telescope set up in his driveway. His education in astronomy began when he was a schoolboy, with pointers from his father, a lab assistant in the botany department at the University of Sydney, and with binoculars borrowed from his uncle. In the late 1950s he began hunting for supernovas with a 5-in. reflecting telescope. In 1967 he built a 10-in. reflector to improve his chances of finding new spots of brightness in distant galaxies. But, says Evans, "I didn't have any success." The problem, he recalls, was that he did not have the proper charts or photographs of the galaxies he was looking at. "I couldn't really tell when a new object appeared," he says, "because there was nothing to compare it with."

In 1980 he got a series of sky charts from a member of the Astronomical Association of Queensland, and things began to happen. He found two supernovas in 1981, four each in 1983 and 1984, one in 1985, three in 1986 and one so far this year. He has compiled this formidable record by spending between 20 and 30 hours a month at his telescope.

Indeed, Evans has so often viewed the hundreds of galaxies he scans each month that he has now become quite familiar with their positions and characteristics. As a result, he explains, "I can look at a lot of galaxies fairly quickly, locate and examine them in perhaps half a minute. Then, if there's anything suspicious, I check the chart. Usually a supernova is fairly obvious." Evans' most scientifically significant supernova find was 1986G, located in a galaxy known as Centaurus A. The supernova was right behind an unusual "belt" of interstellar dust that appears to bisect the galaxy. Professional astronomers have since been analyzing the nature and composition of the belt by determining which wavelengths of light from the supernova are blocked by the dust and which pass through it.

After finding his eleventh supernova, in 1985, Evans retired his aging 10- in. scope. The replacement, a new 16-incher, was given to him by the Commonwealth Scientific and Industrial Research Organization, Australia's national science organization, under a program that donates equipment to top- notch amateurs who are capable of making important contributions to science. Evans remains unaffected by the recognition and acclaim. "It's a humbling experience," he says, "looking at something so awesome."