Early evolution of disrupted asteroid P/2016 G1 (PANSTARRS)

TL;DR

This study analyzes the early dust emission and disruption event of asteroid P/2016 G1 using deep imaging, revealing a short-duration activity likely caused by an impact or disruption, with detailed dust modeling and size estimates.

Contribution

It provides the first detailed modeling of P/2016 G1's dust emission, suggesting impact-induced disruption and estimating dust mass and ejected fragment sizes.

Findings

Dust emission lasted about 24 days.

Approximately 1.7×10^7 kg of dust was ejected.

Parent body fragment size limited to about 50 meters.

Abstract

We present deep imaging observations of activated asteroid P/2016 G1 (PANSTARRS) using the 10.4m Gran Telescopio Canarias (GTC) from late April to early June 2016. The images are best interpreted as the result of a relatively short-duration event with onset about $\mathop{350}_{-30}^{+10}$ days before perihelion (i.e., around 10th February, 2016), starting sharply and decreasing with a $\mathop{24}_{-7}^{+10}$ days (Half-width at half-maximum, HWHM). The results of the modeling imply the emission of $\sim$1.7$\times$10$^7$ kg of dust, if composed of particles of 1 micrometer to 1 cm in radius, distributed following a power-law of index --3, and having a geometric albedo of 0.15. A detailed fitting of a conspicuous westward feature in the head of the comet-like object indicates that a significant fraction of the dust was ejected along a privileged direction right at the beginning of the event, which suggests that the parent body has possibly suffered an impact followed by a partial or total disruption. From the limiting magnitude reachable with the instrumental setup, and assuming a geometric albedo of 0.15 for the parent body, an upper limit for the size of possible fragment debris of $\sim$50 m in radius is derived.