Nongravitational Effects in the Orbital Motions of Several Sunskirting Comets

Yu. A. Chernetenko

Transactions of IAA RAS, issue 53, 67–73 (2020)

DOI: 10.32876/ApplAstron.53.67-73

Keywords: comets, sunskirting comets, period comets, long-period comets, nongravitational effects

Abstract

Sunskirting comets moving in orbits with perihelion distances of q ≈ 0.05 AU, which remained observable during several passages near the Sun, were discovered by the SOHO space observatory. Comets 321P, 322P and 323P were observed in five apparitions, and comet 342P — in four apparitions, comets P/1999 J6 = P/2004 V9 = P/2010 H3 (belong to the Marsden group) and C/1996 X3 = P/2002 S7 = P/2008 N4 (belong to the Kracht I group) — in three apparitions. This makes it possible to determine nongravitational effects in their orbital motions and compare them with the nongravitational effects of other comets to elucidate the possible differences between this group of small bodies and periodic and long-period comets. For six comets, the parameters of nongravitational acceleration (NA) were obtained for several types of its dependence on the heliocentric distance. It turned out that residuals of observations for each comet for all the considered options are close and do not allow to give preference to any of them. Comparison of the NA parameters obtained with the corresponding parameters of all the periodic and long-period comets (JPL data base) was fulfilled. From the point of view of the action of NA on the orbital motions of the comets considered, no features were revealed that would be characteristic only of this group of small bodies.

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