An active asteroid belt causing the UX Ori phenomenon in RZ Psc

TL;DR

This paper reports the discovery of an active asteroid belt around RZ Psc, causing UX Ori-type obscuration events and cyclical variability, indicating a dynamically evolving dust environment beyond the star's formation stage.

Contribution

It introduces the first evidence of an active asteroid belt causing UXOR phenomena in RZ Psc, linking dust dynamics to observed photometric variability.

Findings

8% infrared excess from warm dust within 0.7AU

Dust obscuration events with orbits around 0.5AU

A 12.4-year cyclical photometric variability

Abstract

We report the discovery of mid-infrared excess emission in the young object RZ Psc. The excess constitutes ~8% of its Lbol, and is well fit by a single 500K black-body implying a dust free region within 0.7AU for optically thick dust. The object displays dust obscuration events (UXOR behaviour) with a time-scale that suggests dusty material on orbits of 0.5AU. We also report a 12.4 year cyclical photometric variability which can be interpreted as due to perturbations in the dust distribution. The system is characterized by a high inclination, marginal extinction (during bright photometric states), a single temperature for the warm dust, and an age estimate which puts the star beyond the formation stage. We propose that the dust occultation events present a dynamical view of an active asteroid belt whose collisional products sporadically obscure the central star.