Presentation #411.10 in the session Cometary Volatiles (iPosters).
High-resolution spectra (λ/δλ > 20,000) of Jupiter-family Comet (JFC) 19P/Borrelly were obtained between December 2021 and March 2022 using the Keck/NIRSPEC and IRTF/iSHELL spectrographs. Our study included observations near the most recent perihelion passage of 19P, on 01 February 2022. We report gas rotational temperatures and production rates (or meaningful upper limits) for a suite of trace volatiles: C2H6, HCN, CH3OH, C2H2, NH3, H2CO, and CO. All species were measured simultaneously with H2O and/or its proxy prompt OH emission, permitting robust retrievals of their mixing ratios (abundance ratios). To better place 19P in context, our measured abundance ratios for 19P are compared to those of other JFCs, as well as to comets from the Oort cloud. The JFC dynamical class remains under-represented in ongoing studies of cometary composition, so observations such as those presented here are crucial to expanding our knowledge of the cometary population. To test potential associations among ices in the nucleus, comparisons of spatial distributions for species in 19P having brighter emissions are also presented.
Various co-authors gratefully acknowledge support through the NASA Solar System Observations, Earth and Space Science Fellowship, Emerging Worlds, and Solar System Workings Programs, and by NSF Astronomy and Astrophysics Research Grants.