TESS Discovers a Second System of Transiting Exocomets in the Extreme Debris Disk of RZ Psc
Authors
Adalyn Gibson
Meredith A. MacGregor
Ward S. Howard
Ann Marie Cody
Mark Swain
Jennifer A. Burt
Laura Venuti
Evgenya Shkolnik
Neal J. Turner
Alan Didion
Jaime Nastal
David Makowski
Abstract
We present the TESS discovery of only the second system of transiting exocomets with a sufficient number of events to measure the size distribution in the RZ Psc system, enabling comparisons with the $β$ Pictoris and Solar System size distributions. Twenty-four transits with absorption depths (AD) of 1--20\% were observed across three TESS sectors of the 20-50 Myr K0V star, detected as part of our TESS survey of extreme debris disks identified by their IR excess. We discover that the ADs (and hence exocomet radii) follow a broken power-law cumulative frequency distribution not previously seen in extrasolar contexts but similar to that observed in Solar System Kuiper Belt Object sizes, with power-law slopes above and below the break of $γ_\mathrm{AD>break}$=2.32$\pm$0.12 and $γ_\mathrm{AD
