A Photometric and Dynamic Study of Comet C/2013 A1 (Siding Spring) from Observations at a Heliocentric Distance of ~4.1 AU

TL;DR

This study analyzes the photometric and orbital dynamics of comet C/2013 A1 (Siding Spring) at 4.1 AU, revealing its sustained activity, coma morphology, dust properties, and orbital evolution after a Mars encounter.

Contribution

It provides new measurements of dust and color indices at large heliocentric distance and models the comet's orbital evolution post-Mars encounter.

Findings

Comet shows intense activity at 4.1 AU.

The orbit remains nearly parabolic after planetary encounters.

Dust properties and coma morphology are characterized.

Abstract

An analysis is presented for the photometric data on comet C/2013 A1 (Siding Spring) from observations at a large heliocentric distance (near 4.1 AU). Comet C/2013 A1 (Siding Spring) displays intense activity despite the relatively large heliocentric distance. The morphology of the comet's coma is analyzed. The following parameters are measured: the color indices V-R, the normalized spectral gradient of the reflectivity of the comet's dust S', and the dust production rate Af\r{ho}. A numerical simulation is performed for the evolution of the comet's orbit after a close encounter with Mars. The most probable values are obtained for the Keplerian orbital elements of the comet over a hundred-year period. The comet's orbit remains nearly parabolic after passing the orbits of all the Solar System planets.