Characterization of Active Main Belt Object P/2012 F5 (Gibbs): A Possible Impacted Asteroid

TL;DR

This study characterizes the active main belt object P/2012 F5 (Gibbs), revealing its dust trail, nucleus size, and likely impact origin, with implications for understanding asteroid activity and collisional processes.

Contribution

It provides detailed observational analysis of P/2012 F5 (Gibbs), including dust mass, nucleus size, and evidence supporting a collision-induced activity event.

Findings

Dust trail indicates a mass of ~5 x 10^7 kg.

Nucleus radius estimated at 2.1 km.

Activity likely caused by a collision around July 2011.

Abstract

In this work we characterize the recently discovered active main belt object P/2012 F5 (Gibbs), which was discovered with a dust trail > 7' in length in the outer main belt, 7 months prior to aphelion. We use optical imaging obtained on UT 2012 March 27 to analyze the central condensation and the long trail. We find nuclear B-band and R-band apparent magnitudes of 20.96 and 19.93 mag, respectively, which give an upper limit on the radius of the nucleus of 2.1 km. The geometric cross-section of material in the trail was ~ 4 x 10^8 m^2, corresponding to a dust mass of ~ 5 x 10^7 kg. Analysis of infrared images taken by the Wide-Field Infrared Survey Explorer in September 2010 reveals that the object was below the detection limit, suggesting that it was less active than it was during 2012, or possibly inactive, just 6 months after it passed through perihelion. We set a 1-sigma upper limit on its radius during this time of 2.9 km. P/2012 F5 (Gibbs) is dynamically stable in the outer main belt on timescales of ~ 1 Gyr, pointing towards an asteroidal origin. We find that the morphology of the ejected dust is consistent with it being produced by a single event that occurred on UT 2011 July 7 $\pm$ 20 days, possibly as the result of a collision with a small impactor.