OUTGASSING BEHAVIOR OF C/2012 S1 (ISON) FROM 2011 SEPTEMBER TO 2013 JUNE

Journal Article · Sun Oct 20 00:00:00 EDT 2013 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/776/2/L20· OSTI ID:22224068

Meech, Karen J.; Yang, Bin; Kleyna, Jan; Chiang, Hsin-Fang; Riesen, Timm; Keane, Jacqueline V.; Reipurth, Bo; Hsieh, Henry H. ^[1]; Ansdell, Megan ^[2]; Hainaut, Olivier ^[3]; Vincent, Jean-Baptiste; Boehnhardt, Hermann ^[4]; Fitzsimmons, Alan ^[5]; Rector, Travis ^[6]; Michaud, Peter ^[7]; Milani, Giannantonio ^[8]; Bryssinck, Erik ^[9]; Ligustri, Rolando ^[10]; Trabatti, Roberto ^[11]; Tozzi, Gian-Paolo ^[12] ; others, and

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1. NASA Astrobiology Institute, Honolulu, HI 96822 (United States)
2. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
3. European Southern Observatory, Santiago 19001 (Chile)
4. Max-Planck-Institut fur Sonnensystemforschung, Max-Planck-Strasse 2, D-37191 Katlenburg-Lindau (Germany)
5. Queens University Belfast, Belfast BT7 1NN (United Kingdom)
6. Department of Physics and Astronomy, University of Alaska Anchorage, 3211 Providence Drive, Anchorage, AK 99508 (United States)
7. Gemini Observatory, Northern Operations Center, 670 North A'ohoku Place, Hilo, HI 96720 (United States)
8. Associazione Astronomica Euganea, via Tommaseo, I-35131 Padova (Italy)
9. BRIXIIS Observatory, Eyckensbeekstraat, B-9150 Kruibeke (Belgium)
10. Talmassons Observatory (C.A.S.T.), via Cadorna, I-33030 Talmassons (Italy)
11. Stazione Astronomica Descartes, via Lambrinia 4, I-2013 Chignolo Po' (Italy)
12. INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-40125 Firenze (Italy)

We report photometric observations for comet C/2012 S1 (ISON) obtained during the time period immediately after discovery (r = 6.28 AU) until it moved into solar conjunction in mid-2013 June using the UH2.2 m, and Gemini North 8 m telescopes on Mauna Kea, the Lowell 1.8 m in Flagstaff, the Calar Alto 1.2 m telescope in Spain, the VYSOS-5 telescopes on Mauna Loa Hawaii and data from the CARA network. Additional pre-discovery data from the Pan STARRS1 survey extends the light curve back to 2011 September 30 (r = 9.4 AU). The images showed a similar tail morphology due to small micron sized particles throughout 2013. Observations at submillimeter wavelengths using the James Clerk Maxwell Telescope on 15 nights between 2013 March 9 (r = 4.52 AU) and June 16 (r = 3.35 AU) were used to search for CO and HCN rotation lines. No gas was detected, with upper limits for CO ranging between 3.5-4.5 × 10{sup 27} molecules s{sup –1}. Combined with published water production rate estimates we have generated ice sublimation models consistent with the photometric light curve. The inbound light curve is likely controlled by sublimation of CO{sub 2}. At these distances water is not a strong contributor to the outgassing. We also infer that there was a long slow outburst of activity beginning in late 2011 peaking in mid-2013 January (r ∼ 5 AU) at which point the activity decreased again through 2013 June. We suggest that this outburst was driven by CO injecting large water ice grains into the coma. Observations as the comet came out of solar conjunction seem to confirm our models.

• OSTI ID: 22224068
• Journal Information: Astrophysical Journal Letters, Vol. 776, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
CARBON DIOXIDE
CARBON MONOXIDE
COMETS
DEGASSING
DIAGRAMS
HYDROCYANIC ACID
IMAGES
SUBLIMATION
TELESCOPES
WATER