# # Program information file # PROGRAM_ID 2024B083 PROGRAM_TITLE Probing the Origins: A High-Resolution Infrared Study of Halley-Type Comet 13P/Olbers Using iSHELL. PROGRAM_INV1 Mohammad Saki PROGRAM_INV2 Erika Gibb PROGRAM_INV3 Neil Dello Russo PROGRAM_INV4 Nathan Roth PROGRAM_INV5 Ron Vervack PROGRAM_SCICAT comets PROGRAM_ABSTRACT_BEG We propose to use iSHELL to measure the coma volatile composition of Halley-type comet 13P/Olbers. iSHELL's cross-dispersed capability enables us to efficiently sample multiple emission lines of targeted molecules such as H2O, C2H6, C2H2, CH3OH, HCN, H2CO, NH3, OCS, and OH with only three settings. We emphasize four equally important goals: [1] to measure the volatile composition of one of the most underrepresented dynamical classes of comets and provide insights into their Oort cloud origin and thermal processing; [2] to understand spatial outgassing patterns and nucleus associations, thus revealing the nature of volatile release mechanisms; [3] to support the JWST mission by supplying crucial observational data at smaller heliocentric distances; and [4] to compare observed volatile abundances with protoplanetary disk [PPD] model predictions, thereby bridging gaps in our understanding of solar system formation and evolution. We will use three iSHELL settings: Lcustom [~2.8-3.1 um, sampling H2O, HCN, NH3, and C2H2]; Lp1 [~3.2-3.6 um, sampling C2H6, CH3OH, H2CO, and OH*, a proxy for the production and spatial distribution of its parent, H2O]; and M2 [~4.5-5.2 um, sampling H2O and OCS]. We will use the 3.46 um filter to guide on 13P with Kyle during the day, as this filter covers generally strong gas emission. The 2024B semester provides a rare [and excellent] opportunity to measure 13P parent volatile abundances in a rare Halley-type comet. Owing to its high resolving power, spectral coverage, flexible daytime scheduling, and superior M-band guiding, these studies can only be done with iSHELL at NASA-IRTF. PROGRAM_ABSTRACT_END