Thermal Infrared and Optical Photometry of Asteroidal Comet C/2002 CE$_{10}$

TL;DR

This study presents optical and thermal observations of the inactive, dark, and red-colored asteroidal comet C/2002 CE$_{10}$, revealing its physical properties and suggesting its origin and relation to Damocloids in the Oort Cloud.

Contribution

It provides detailed photometric, rotational, and thermal data of C/2002 CE$_{10}$, highlighting its surface composition, rotation period, and size, and discusses its possible origin and classification.

Findings

C/2002 CE$_{10}$ has a rotation period of 8.19 hours.

Its diameter is approximately 17.9 km with a very low albedo of 0.03.

The surface is dark and redder, likely due to surface aging or original composition.

Abstract

C/2002 CE$_{10}$ is an object in a retrograde elliptical orbit with Tisserand parameter $-0.853$ indicating a likely origin in the Oort Cloud. It appears to be a rather inactive comet since no coma and only a very weak tail was detected during the past perihelion passage. We present multi-color optical photometry, lightcurve and thermal mid-IR observations of the asteroidal comet. \textcolor{blue}{ With the photometric analysis in $BVRI$, the surface color is found to be redder than asteroids, corresponding to cometary nuclei and TNOs/Centaurs. The time-resolved differential photometry supports a rotation period of 8.19$\pm$0.05 h. The effective diameter and the geometric albedo are 17.9$\pm$0.9 km and 0.03$\pm$0.01, respectively, indicating a very dark reflectance of the surface. The dark and redder surface color of C/2002 CE$_{10}$ may be attribute to devolatilized material by surface aging suffered from the irradiation by cosmic rays or from impact by dust particles in the Oort Cloud. Alternatively, C/2002 CE$_{10}$ was formed of very dark refractory material originally like a rocky planetesimal. In both cases, this object lacks ices (on the surface at least). The dynamical and known physical characteristics of C/2002 CE$_{10}$ are best compatible with those of the Damocloids population in the Solar System, that appear to be exhaust cometary nucleus in Halley-type orbits. The study of physical properties of rocky Oort cloud objects may give us a key for the formation of the Oort cloud and the solar system.