Volatile Vehicles to Past: Characterizing the Activity of Long Period Comets
PI:
Erica Bufanda
Co-I(s):
Karen Meech, Jan Kleyna, Jacqueline keane, Olivier Hainaut, Bin Yang, Rob Weryk, Richard Wainscoat, Marco Micheli
Abstract
Long period comet (LPC) nuclei are important in the context of solar system formation because their nuclei are the least altered primitive bodies that likely retain the chemical signatures of their birthplaces in the proto-planetarydisk. In 1951 Jan Oort hypothesized that Oort cloud LPCs fade upon their first passage into the inner solar system and that there should be physical differences between dynamically old (DO) and dynamically new (DN)comets. Recent studies suggest that DN LPCs may not fade but instead disrupt. To date, these issues have not been resolved. This is because LPC nuclei are difficult to characterize because activity creates a dust coma affecting our ability to observe the nucleus and LPCs are rarely discovered inactive. Analyzing LPC colors may be an efficient method for understanding an LPC’s dynamical evolution if we can effectively interpret how activity affects the colors we see. UH is the leader for discovering LPCs with the PanSTARRS and ATLAS all-sky-surveys. Their efficiency allows us to detect fainter objects further out in their orbits, significantly increasing the time for follow-up observations and construction of their heliocentric light curves to model their activity. For my thesis I will use data from these surveys and obtain new data from observatories on Maunakea and elsewhere to conduct a study of>100 long period comets. I will first compare the physical characteristics (activity + color evolution) between LPCs that have orbits that suggest they are newly perturbed bodies from the Oort Cloud (“dynamically new”) and LPCs with orbits that suggest they have spent more time in the inner solar system (“dynamically old”). Secondly, for dynamically new comets I will assess if LPCs fade or disintegrate after their first inner solar system passage. This request is for 14.3 hours with Gemini/GMOS-N to obtain grizY photometry and spectra to characterize the surface and dust mineralogy for 18-20 Standard ToO targets for essential initial characterization, model sublimation activity and to obtain astrometry to secure the orbit for the full visibility period.