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The organic composition of Comet C/2001 A2 (LINEAR): I. Evidence for an unusual organic chemistry |
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| Authors: | Karen Magee-Sauer Michael J. Mumma Neil Dello Russo Boncho P. Bonev G.L. Villanueva |
| Affiliation: | a Department of Physics and Astronomy, Rowan University, Glassboro, NJ 08028-1701, USA b Solar System Exploration Division, NASA Goddard Space Flight Center, Mailstop 693, Greenbelt, MD 20771, USA c Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723-6099, USA d Department of Physics and Astronomy, University of Missouri-St. Louis, St. Louis, MO 63121, USA e Department of Physics, Catholic University of America, Washington, DC 20064, USA |
| Abstract: | We used the NIRSPEC instrument on the Keck-2 telescope atop Mauna Kea, HI to observe Comet C/2001 A2 (LINEAR) in a Target of Opportunity campaign on UT 2001 July 9.5, 10.5 August 4.4, 10.5. We measured seven organic parent volatiles (C2H6, C2H2, HCN, CH4, CO, CH3OH, H2CO) simultaneously with H2O. We obtained absolute production rates and relative abundances for parent volatiles, and also measured rotational temperatures for several of these species. The chemical composition of C/2001 A2 differs substantially from any comet we have observed to date. The abundances we measure (relative to H2O) for C2H6, C2H2, HCN, and CH3OH are enriched by a factor of ∼2 to 3 in C/2001 A2 compared with most comets in our database. Other molecular species were detected within the typical range of measured abundances. C/2001 A2 presented a unique opportunity to study the chemistry of a fragmenting comet where pristine areas are exposed to the Sun. |
| Keywords: | Comets Comets, composition Spectroscopy |
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