Orbital evolution under action of fast interstellar gas flow

TL;DR

This paper investigates how fast interstellar gas flow affects the orbital evolution of interplanetary dust particles, revealing that it causes a decrease in semi-major axis and influences the stability of dust rings beyond planets.

Contribution

It provides a comprehensive, physics-respecting analysis of the secular orbital evolution under interstellar gas flow, improving upon previous models and highlighting the importance of this effect beyond planetary regions.

Findings

Semi-major axis decreases under interstellar gas flow.

Low inclination dust orbits are unstable due to eccentricity growth.

Interstellar gas flow significantly influences dust dynamics beyond planets.

Abstract

Orbital evolution of an interplanetary dust particle under action of an interstellar gas flow is investigated. Secular time derivatives of the particle orbital elements, for arbitrary orbit orientation, are presented. An important result concerns secular evolution of semi-major axis. Secular semi-major axis of the particle on a bound orbit decreases under the action of fast interstellar gas flow. Possible types of evolution of other Keplerian orbital elements are discussed. The paper compares influences of the Poynting-Robertson effect, the radial solar wind and the interstellar gas flow on dynamics of the dust particle in outer planetary region of the Solar System and beyond it, up to 100 AU. Evolution of putative dust ring in the zone of the Edgeworth-Kuiper belt is studied. Also non-radial solar wind and gravitational effect of major planets may play an important role. Low inclination orbits of micron-sized dust particles in the belt are not stable due to fast increase of eccentricity caused by the interstellar gas flow and subsequent planetary perturbations - the increase of eccentricity leads to planet crossing orbits of the particles. Gravitational and non-gravitational effects are treated in a way which fully respects physics. As a consequence, some of the published results turned out to be incorrect. Moreover, the paper treats the problem in a more general way than it has been presented up to now. The influence of the fast interstellar neutral gas flow might not be ignored in modeling of evolution of dust particles beyond planets.