Activity of (6478) Gault during January 13 - March 28, 2019

TL;DR

This study reports photometric observations of active asteroid (6478) Gault from January to March 2019, revealing comet-like activity, color variations, and a rotational period of approximately 1.79 hours, contributing to understanding its activity mechanisms.

Contribution

First detailed photometric analysis of (6478) Gault's activity during early 2019, including tail structure, color variations, and rotation period estimation.

Findings

Detected persistent comet-like tail structures.

Measured $Af ho$ values indicating activity levels.

Estimated rotational period of about 1.79 hours.

Abstract

We present the results of photometric observations of active asteroid (6478) Gault performed at heliocentric distances from 2.46 to 2.30 au and geocentric distances from 1.79 to 1.42 au between January 15 and March 28, 2019. Observations were carried out at the 2.5-m telescope of SAI MSU (CMO) on January 15, 2019 and at the 1.3-m and 0.61-m telescopes (SPb) on February 6 and March 28, 2019, respectively. The direct images of the asteroid were obtained with the broad-band B, V and R filters. Comet-like structures were detected at all observation dates. Colour maps were built and colour variations along the tail for the observation made on January 15, 2019 were analyzed. The $Af\rho$ was calculated for the R filter, The evaluated value varies from 47 to 32 cm for the period from January to the end of March, 2019. The rotational period of the body is estimated from the light curve by different methods and is about 1.79 hr. Possible mechanisms of triggering Gault's activity are discussed.