Program: GN-2011A-Q-15

The recently-identified main-belt comets (MBCs) exhibit cometary activity yet are dynamically indistinguishable from main-belt asteroids. Studies of these apparently icy objects so close to the Sun have significant implications for understanding the distribution of volatile material in our solar system as well as the origin of Earth?s water. We seek optical imaging time on Gemini North to characterize the nucleus of MBC P/2008 R1 (Garradd). P/Garradd is one of the least well-characterized of the known MBCs, as it was dominated by coma at the time of its discovery and only observed once while inactive, meaning that very little is known about the nucleus?s physical properties. The comet will be ideally placed during the upcoming semester, being distant enough from the Sun that significant activity is not expected, giving us our best chance at a clear view of the nucleus. Queue-scheduled observations using Gemini are requested to determine various key physical properties of the nucleus, including its physical size, phase function, and photometric range, which will be invaluable for placing it in the context of the other known MBCs.