Anomalous eclipses of the young star RW Aur A

TL;DR

This study presents photometric, polarimetric, and spectroscopic observations of RW Aur A, revealing that its dimming events are caused by large dust screens eclipsing the star, with characteristics similar to UX Ori-type stars.

Contribution

It provides new observational evidence that RW Aur A's dimming is due to large dust screens, expanding understanding of star dimming mechanisms beyond typical UX Ori stars.

Findings

Dimming caused by dust screens larger than those in UXORs

Brightness decreased by over 4.5 magnitudes during dimming events

Polarization in I-band reached up to 30% during dimming

Abstract

Results of UBVRIJHKLM photometry, VRI polarimetry and optical spectroscopy of a young star RW Aur A obtained during 2010-11 and 2014-16 dimming events are presented. During the second dimming the star decreased its brightness to \Delta V > 4.5 mag, polarization of its light in I-band was up to 30%, and color-magnitude diagram was similar to that of UX Ori type stars. We conclude that the reason of both dimmings is an eclipses of the star by dust screen, but the size of the screen is much larger than in the case of UXORs.