Program: GN-2011B-Q-17

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 volatiles in our solar system as well as the origin of Earth?s water. We seek optical imaging time on Gemini North to monitor four of the known MBCs to characterize their activity profiles. Precise characterization of when MBCs are active and when they are not is essential for understanding their physical nature, and in particular, evaluating hypotheses regarding the modulation of their activity. This information, in turn, will have implications for determining the plausibility of impact activation for producing MBC activity. Monitoring of the activity (or lack thereof) of 176P, 238P, P/Garradd, and P/La Sagra with Gemini in 2011B will provide strong constraints on their active behavior, in turn giving insights into the physical mechanisms underlying that behavior.