Program: GN-2006B-Q-8

Direct observations of massive stars - before they explode - provide a model free identification of SN progenitors. Such studies require the combination of a deep, high-resolution image of the SN location, serendipitously obtained before it exploded, with a precise localization of the SN (after it exploded) to enable us to select the correct progenitor from among the stars in the pre-explosion SN images. After decades of effort, {\it only six SN progenitors} have so far been detected (4 during the last 3 years). Once or twice a year a SN is discovered in an area previously observed by {\it HST}. Many of these rare opportunities were lost, though, lacking precise SN localization from post-explosion high-quality imaging. The few recent identifications were mainly based on repeat {\it HST} post-explosion imaging for this purpose. A better alternative for SN localization is now provided by laser-guide-star assisted adaptive optics systems (LGS-AO), as we have demonstrated using the Keck LGS system. Here, we propose to use NIRI+ALTAIR in LGS mode to localize nearby SNe and identify their progenitors. A minimal Gemini allocation (1 hour) leveraged by superb archival {\it HST} data will provide exciting results, and improve our chances not to lose any of the few rare SNe for which direct progenitor detection is possible. With each additional progenitor identified and studied, we move closer to a robust mapping of specific progenitors to each SN class, a key to understand the physics of these powerful cosmic explosions.