The Dust Environment of Main-Belt Comet P/2010 R2 (La Sagra)
Abstract
We present a model of the dust environment of Main-Belt Comet P/2010 R2 (La Sagra) from images acquired during the period 2010 October-2011 January. The tails are best simulated by anisotropic ejection models, with emission concentrated near the nucleus south pole, the spin axis having an obliquity near 90°, indicative of a possible seasonally driven behavior. The dust mass loss rate increases rapidly shortly before perihelion, reaching a maximum value of ~4 kg s-1, and maintaining a sustained, cometary-like, activity of about 3-4 kg s-1 up to at least 200 days after perihelion, the date of the latest observation. The size distribution function is characterized by particles in the 5 × 10-4 cm to 1 cm radius range, assuming a time-constant power-law distribution with an index of -3.5. The ejection velocities are compatible with water-ice sublimation activity at the heliocentric distance of 2.7 AU, with values of 10-20 cm s-1 for particle radius of 1 cm, and inverse square root dependence on particle size, typical of hydrodynamical gas drag.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 2011
- DOI:
- 10.1088/2041-8205/738/1/L16
- Bibcode:
- 2011ApJ...738L..16M
- Keywords:
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- comets: individual: P/2010 R2 (La Sagra);
- methods: numerical;
- minor planets;
- asteroids: general