# # Program information file # PROGRAM_ID 2024A043 PROGRAM_TITLE Post-Outburst Coma Evolution of an Active Centaur with IRTF/SpeX PROGRAM_INV1 Theodore Kareta PROGRAM_INV2 PROGRAM_INV3 PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT Centaurs / TNOs / KBOs PROGRAM_ABSTRACT_BEG As the direct evolutionary precursors to most of the inner Solar System's Jupiter Family Comets, the modern properties of the Centaurs of the middle and outer Solar System are of great interest to help to understand the physical, chemical, and dynamical evolution that takes place as objects migrate from one population into the other. One particular interest is the nature of and processes that drive some Centaurs to be active, displaying ongoing mass loss and cometary comae, despite their great distances from the Sun -- and thus their low surface temperatures. While some of these Active Centaurs behave predictably, brightening and becoming more active as they approach the Sun, the activity pattern of others are dominated by large outbursts followed by periods of quiescence or low activity. This outburst-centric activity mode is not seen in the Inner Solar System, and understanding what processes drive it is thought to be critical to understanding how these objects are changed en-route from the Trans-Neptunian Region. The primary goal of this proposal is to investigate the evolution of the reflectance spectrum of the coma of an Active Centaur throughout and after an outburst in a ToO mode. The SpeX spectra will be modeled to estimate the grain size distribution of the outburst coma and how it evolved over time, facilitating an understanding of the mechanisms by which the grains were ejected off the surface. PROGRAM_ABSTRACT_END