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A multi-instrument study of Comet C/2009 P1 (Garradd) at 2.1 AU (pre-perihelion) from the Sun

Villanueva, G. L. and Mumma, M. J. and DiSanti, M. A. and Bonev, B. P. and Paganini, L. and Blake, G. A. (2012) A multi-instrument study of Comet C/2009 P1 (Garradd) at 2.1 AU (pre-perihelion) from the Sun. Icarus, 220 (1). pp. 291-295. ISSN 0019-1035.

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We observed Comet C/2009 P1 (Garradd) on UT 2011 September 8th and 9th at a large heliocentric distance of 2.1 AU upon its entry to the inner Solar System. The observations were performed using high-resolution infrared spectrometers (NIRSPEC at Keck II and CSHELL at IRTF), allowing us to obtain strong detections of H_2O, CO, CH_4 and HCN and sensitive upper-limits for C_2H_6, C_2H_2, NH_3 and HC_3N. We oriented the slit at 45° from the projected Sun–comet vector and obtained spatial profiles of H_2O, CH_4, and HCN that revealed notable differences among these species. In particular, we observed a strong excess of water in the projected sunward direction, probably due to a solar-activated jet releasing water-rich icy grains.

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Blake, G. A.0000-0003-0787-1610
Additional Information:© 2012 Elsevier Inc. Received 20 January 2012; Revised 23 March 2012; Accepted 26 March 2012; Available online 13 April 2012. G.L.V., M.J.M., M.A.D. and B.P.B. acknowledge support from NASA’s Astrobiology Institute (RTOP 344-53-51), and NASA’s Planetary Atmospheres and Astronomy Programs (RTOPs 344-32-07, 08-PAST08-0034, 08-PATM08-0031). BPB acknowledges support from the NSF Astronomy and Astrophysics Grants Program (AST-0807939) and LP acknowledges support from the NASA Postdoctoral Program. GAB acknowledges support from the NASA Origins of Solar Systems program. The data presented herein were obtained at the W.M. Keck Observatory operated as a scientific partnership among CalTech, UCLA, and NASA. This observatory was made possible by the generous financial support of the W.M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.
Funding AgencyGrant Number
NASARTOP 344-53-51
NASARTOP 344-32-07
NASA Postdoctoral ProgramUNSPECIFIED
Subject Keywords:Comets, Composition; Spectroscopy; Infrared observations; Astrobiology
Issue or Number:1
Record Number:CaltechAUTHORS:20120807-152139571
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Official Citation:G.L. Villanueva, M.J. Mumma, M.A. DiSanti, B.P. Bonev, L. Paganini, G.A. Blake, A multi-instrument study of Comet C/2009 P1 (Garradd) at 2.1 AU (pre-perihelion) from the Sun, Icarus, Volume 220, Issue 1, July 2012, Pages 291-295, ISSN 0019-1035, 10.1016/j.icarus.2012.03.027. (
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:32993
Deposited By: Aucoeur Ngo
Deposited On:07 Aug 2012 22:40
Last Modified:03 Oct 2019 04:05

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