Specific features of orbits of Kreutz dwarf comets

Abstract

Angular orbital parameters of Kreutz sungrazing comets are considered. Three groups of Kreutz dwarf comets are distinguished based on the positioning of orbit poles, and the motion of fragments from group A is modeled numerically. It is found that Kreutz dwarf comets have a very large parameter А₃ of nongravitational acceleration. This may be associated with sublimation of substances more refractory than water ice at extremely short heliocentric distances. It is demonstrated that the nongravitational acceleration of Kreutz dwarf comets is asymmetric with respect to perihelion, and the perturbing function maximum is observed ~15 min after the perihelion passage.