Observations and analysis of a curved jet in the coma of comet 67P/Churyumov-Gerasimenko

TL;DR

This study investigates a curved dust jet from comet 67P, revealing its formation due to dust particle size and source location, combining observations and simulations to understand its dynamics.

Contribution

The paper presents a combined observational and simulation analysis of a curved jet on comet 67P, highlighting the role of dust size and source location in jet formation.

Findings

The curved jet results from dust particles of 0.1-1 mm size.

The jet's spiral shape is due to source location near the nucleus equator.

Dust accelerates to a terminal speed of a few m/s.

Abstract

We analyze the physical properties and dynamical origin of a curved jet of comet 67P/Churyumov-Gerasimenko that was observed repeatedly in several nucleus rotations starting on May 30 and persisting until early August, 2015. We simulated the motion of dust grains ejected from the nucleus surface under the influence of the gravity and viscous drag effect of the expanding gas flow from the rotating nucleus. The formation of the curved jet is a combination of the size of the dust particles (~0.1-1 mm) and the location of the source region near the nucleus equator. This enhances the spiral feature of the collimated dust stream after the dust is accelerated to a terminal speed on the order of m/s.