A Dwarf Protoplanetary Disk around XZ Tau B

TL;DR

This paper reports the discovery of a small, dwarf protoplanetary disk around XZ Tau B with a central cavity, indicating potential planet formation, and highlights its rapid evolution and observability.

Contribution

It presents the first imaging of a dwarf protoplanetary disk with detailed features, demonstrating its potential for studying fast disk evolution and planet formation.

Findings

Disk radius ~3.4 au with a 1.3 au cavity

Disk mass sufficient for planetary system formation

Observable changes in months due to small size

Abstract

We report the discovery of a dwarf protoplanetary disk around the star XZ Tau B that shows all the features of a classical transitional disk but on a much smaller scale. The disk has been imaged with the Atacama Large Millimeter/Submillimeter Array (ALMA), revealing that its dust emission has a quite small radius of ~ 3.4 au and presents a central cavity of ~ 1.3 au in radius that we attribute to clearing by a compact system of orbiting (proto)planets. Given the very small radii involved, evolution is expected to be much faster in this disk (observable changes in a few months) than in classical disks (observable changes requiring decades) and easy to monitor with observations in the near future. From our modeling we estimate that the mass of the disk is large enough to form a compact planetary system.