First Results from TESS Observations of Comet 46P/Wirtanen

TL;DR

This paper presents initial findings from TESS observations of comet 46P/Wirtanen, highlighting a detailed outburst profile, gas and dust velocities, and a newly discovered dust trail, providing valuable insights into comet activity.

Contribution

First high-cadence, long-duration TESS observations of comet 46P/Wirtanen revealing detailed outburst characteristics and a new dust trail.

Findings

Recorded a two-phase outburst with a 0.5 mag brightening.

Gas velocities peaked at 800 m/s during the outburst.

Discovered a previously unreported dust trail extending beyond 24°.

Abstract

We report on initial results from 20 days' worth of TESS spacecraft observations of comet 46P/Wirtanen. The long-duration, high-cadence measurements show a 2018 September 26 outburst that exhibited a two-phase, 0.5 mag brightening profile, and may be the best temporally characterized natural outburst ever recorded. Gas velocities from the outburst peaked at 800 m s$^{-1}$, while dust expanded at only 10s of m s$^{-1}$. Coadded images also revealed a previously unreported dust trail that extends beyond the 24$^\circ$ field of view.