Cometary Orbit Determination and Nongravitational Forces

نویسندگان

  • D. K. Yeomans
  • P. W. Chodas
  • M. Królikowska
چکیده

The accuracies of the orbits and ephemerides for active comets are most often limited by imperfectly modeled rocket-like accelerations experienced by active comets as a result of the outgassing cometary nucleus near perihelion. The standard nongravitational acceleration model proposed by Marsden et al. (1973) has been updated by allowing the nucleus outgassing to act asymmetrically with respect to perihelion, providing for time-dependent effects through the precession of the cometary nucleus and accounting for the outgassing from discrete surface areas on a rotating nucleus. While the most accurate nongravitational models will likely require a detailed a priori knowledge of a comet’s surface activity and rotation characteristics, it is becoming possible to use only astrometric data to actually solve for some of the parameters that describe the comet’s outgassing and rotational characteristics.

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تاریخ انتشار 2005