Prof honors supernova discovery

In experimental science -- as in life -- things do not always work out as planned. But, as Physics Professor Emeritus Alfred Mann explained Wednesday, perhaps that's for the best. As part of the Physics Department's "February Jubilee" celebration, Mann gave a talk commemorating the 10th anniversary of the discovery of Supernova 1987A -- an explosion of a star that has run out of nuclear fuel. Nearly 150 people attended the lecture, entitled "Neutrino Astronomy and Supernova 1987A: The Birth of a New Science," in the David Rittenhouse Laboratory. In describing the explosion of the supernova, Mann said he was serving as co-leader of a group of University professors conducting research in Japan when the cosmic event occurred February 23, 1987. He added that the original focus of the group's study was not the discovery of the supernova but rather the collection and study of neutrinos -- the smallest known interacting parts of matter -- from solar emissions. But unusually high readings of neutrino levels from the Japanese lab's recorders following the explosion led to an unexpected discovery. An overwhelming fraction of the supernova's emissions -- 99 percent -- consisted of neutrinos, Mann noted. An Ohio laboratory conducting similar experiments provided similar data -- and the science of neutrino astrophysics was born. A Type II supernova -- such as the one that occurred in 1987 -- takes place when a star exhausts its nuclear fuel and its core collapses, producing a mass explosion. The light from this explosion is visible in neighboring galaxies as new stars appear. The explosion of Supernova 1987A was particularly significant because it occurred in the Large Magellan Cloud -- a satellite galaxy of the Milky Way close enough for scientists on Earth to optically observe the event. Physics Professor Gene Beier noted that the discovery was especially significant because it is "an event which happens near our galaxy so rarely." Before 1987, Johannes Kepler recorded the last observed supernova occurrence in 1604. Engineering sophomore Yasmine Beg, a resident of the Science and Technology Wing, described Mann's talk as "very informative." In conjunction with the anniversary, College junior and Physics major John Parker, a program assistant for the Science and Technology Wing, assisted in setting up a World Wide Web site to promote the celebration. The Physics Department's Web site currently features a schedule of this month's events -- including three talks today on the subject of supernovas. Cornell University Professor Hans Bethe, a 1967 Nobel laureate, will give a lecture at 4:30 p.m. in Room A1 of DRL. Physics Chairperson Paul Langacker stressed that all members of the University community are invited to attend. And local high school science teachers have also been invited as part of an effort of community outreach. Mann will soon publish Shadow of a Star: The Neutrino Story of Supernova 1987A, a book about his experience.