Orbital evolution under the action of fast interstellar gas flow with a non-constant drag coefficient

摘要: The acceleration of a spherical dust particle as result interstellar gas flow depends on the drag coefficient, which is, for given and gas, specific function relative speed with respect to gas. We investigate motion in case when caused by (with variability coefficient taken into account) represents small perturbation gravity central star. present secular time derivatives Keplerian orbital elements under action from flow, linear account, arbitrary orbit orientations. semimajor axis is decreasing an constant also such linearly variable coefficient. decrease slower minimal maximal values are determined. In planar case, velocity lies plane particle, always approaches position value transversal component vector measured at perihelion. The properties evolution derived consistent numerical integrations equation motion. main difference between evolutions coefficients axis. decreases more slowly This agreement analytical results. If much larger than then approximation dependence usable most (not too close zero) molecular ratios (Mach numbers).