"A Supernova Riddle"
Physics and Astronomy Seminar with Professor Douglas Leonard of San Diego State University
We know that it happens, but we don't know how Nature does it. Roughly once per second in the observable universe, a massive star's inner core implodes under its own weight and then explodes as a supernova, announcing its demise with an optical display that for weeks rivals the combined brilliance of all of the other stars in its parent galaxy. These explosions synthesize and expel heavy elements, heat the interstellar medium, trigger vigorous bursts of star formation, create neutron stars and sometimes black holes, and produce energetic cosmic rays. And yet we must acknowledge basic ignorance: We do not know how-- or even precisely which --stars explode. Using recent observations that demand the resolving power of the Hubble Space Telescope and the light-gathering capability of the world's largest ground-based telescopes, I will argue that despite the mystery that enshrouds these cosmic blasts, fundamental advances on both fronts are being made.
Cookies and tea will precede the seminar, at 4:15 p.m. in 204 Merrill.