A study of the original orbits of ``hyperbolic'' comets
Abstract
The problem of hyperbolic incoming orbits for singleapparition comets is investigated. In this context the effect of nongravitational acceleration on cometary dynamics was analyzed for the sample of 33 ``hyperbolic'' comets. The orbital elements of each cometary orbit were determined by the least squares procedure based on positional observations. These osculating orbital elements serve as a basis for the determination of the incoming orbits. The new method of estimating the uncertainties of (1/a)_ori based on a statistical approach to the orbit determinations is applied. For sixteen comets it was possible to determine the nongravitational effects and original ``nongravitational'' orbits. We show that for almost all the comets with detectable nongravitational effects the incoming barycentric orbits changed from hyperbolic to elliptical when the nongravitational effects were included. However, it was also ascertained that excess velocity at great distance are not cancelled by the nongravitational acceleration itself. We show that the nongravitational effects are responsible for small modifications of the osculating elements (mainly eccentricity), which are sufficient, however, to obtain the elliptic original orbits for comets recognized in the literature as hyperbolic.
 Publication:

Astronomy and Astrophysics
 Pub Date:
 September 2001
 DOI:
 10.1051/00046361:20010945
 Bibcode:
 2001A&A...376..316K
 Keywords:

 SOLAR SYSTEM;
 COMETS;
 LONGPERIOD;
 NONGRAVITATIONAL EFFECTS