A Multiwavelength Investigation of Sungrazing Comet Lovejoy (C/2011 W3)
Abstract
Comet Lovejoy (C/2011 W3) was the first Kreutz sungrazing comet in the modern telescopic era (since 1970) to survive perihelion, although the extent to which the nucleus survived remains unclear. We used observations by SOHO and STEREO obtained near perihelion as well as observations we acquired with the Hubble Space Telescope, Spitzer Space Telescope, Swift, Siding Spring Observatory, Las Campanas Observatory, and Lowell Observatory in the days and weeks after perihelion (2011 December 16) to characterize the effects of the perihelion passage (q~1.2 solar radii) and attempt to constrain properties of the nucleus and dust. Lovejoy brightened steadily until perihelion, reaching an apparent magnitude of at least -2.5 in the SOHO field of view. The lightcurve exhibited three peaks shortly after perihelion (~0.35, ~0.85, and ~1.40 days). From the time of the last peak until Lovejoy left the STEREO fields of view more than a week later, the near-nucleus region was ~4 mag brighter post-perihelion than at comparable distances pre-perihelion, and the central condensation became elongated. These behaviors strongly suggest that Lovejoy fragmented (or possibly disintegrated) in one or more events near or shortly after perihelion. Preliminary analysis of Hubble, Swift, and Spitzer images did not reveal any surviving nuclear fragments larger than ~50 m, although the larger than expected uncertainty in the orbit does not conclusively rule out their existence. Significant quantities of dust were still visible in Spitzer data acquired in early 2012 February. Analysis of the data is ongoing and new results will be reported. Telescope time was granted under HST program DD 12792, Spitzer program 80237, and Swift target ID 32251.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFMSH13B2258K
- Keywords:
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- 6040 PLANETARY SCIENCES: COMETS AND SMALL BODIES / Origin and evolution;
- 6210 PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS / Comets;
- 6025 PLANETARY SCIENCES: COMETS AND SMALL BODIES / Interactions with solar wind plasma and fields;
- 6023 PLANETARY SCIENCES: COMETS AND SMALL BODIES / Comets: dust tails and trails