Resolved photometry of the binary components of RW Aur

TL;DR

This study presents resolved photometry of the RW Aur binary during a deep dimming event, revealing dust eclipse of RW Aur A and variability in RW Aur B over 20 years, using new observations from a 2.5m telescope.

Contribution

First resolved UBVRI photometry of RW Aur during a dimming event, showing dust eclipse of RW Aur A and long-term variability of RW Aur B.

Findings

RW Aur A dimmed by about 3 magnitudes across all bands.

Dimming caused by dust particles larger than 1 micron.

RW Aur B brightened by approximately 0.7 magnitudes over 20 years.

Abstract

Resolved UBVRI photometry of RW Aur binary was performed on November 13/14, 2014 during the deep dimming of RW Aur with a newly installed 2.5 meter telescope of the Caucasus observatory of Lomonosov Moscow State University at the mount Shatzhatmaz. At that moment RW Aur A was $\simeq 3^m$ fainter than in November 1994 in all spectral bands. We explain the current RW Aur A dimming as a result of eclipse of the star by dust particles with size $>1 \mu m.$ We found that RW Aur B is also a variable star: it was brighter than 20 years ago at $0.7^m$ in each of UBVRI band (gray brightening).