geminiann09003 — Announcement
First Supernova Discovered with Laser Guide Star Adaptive Optics
22 January 2009: Stuart Ryder, Australian Gemini Scientist at the Anglo-Australian Observatory, and colleagues from Europe and South Africa have used the 8-meter Gemini North telescope in Hawai‘i and its laser guide star adaptive optics system to reveal a supernova (SN 2008cs) in a galaxy (IRAS 17138-1017) 250 million light-years away (Figure 1). This is the first supernova to be discovered using laser guide star adaptive optics. Along the way, the researchers also turned up a second, “historical” supernova, SN 2004iq, in the same galaxy. Stellar evolution theory, along with the recent identifications of actual supernova progenitors, indicates that only stars more massive than ~8Msun will end their lives as core-collapse supernovae. Assuming that the ratio of such stars to less massive ones—the initial mass function—is the same everywhere in the universe, then the observed rate of supernovae can be used to gauge the rate of star formation, across a wide range of …