The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. V. R Coronae Borealis Stars in the Large Magellanic Cloud

TL;DR

This paper catalogs 23 R Coronae Borealis stars in the Large Magellanic Cloud, including 6 new candidates, and explores their relation to DY Per stars among carbon-rich long-period variables.

Contribution

It provides the first comprehensive catalog of R CrB stars in the LMC, including new candidates and analysis of their connection to DY Per stars.

Findings

23 R CrB stars identified in the LMC

6 new RCB candidates discovered

DY Per candidates form a continuum with other carbon-rich variables

Abstract

The fifth part of the OGLE-III Catalog of Variable Stars presents 23 R CrB (RCB) stars in the Large Magellanic Cloud (LMC). 17 of these objects have been spectroscopically confirmed by previous studies, while 6 stars are new candidates for RCB variables. We publish the VI multi-epoch OGLE photometry for all objects. We use the sample of carbon-rich long-period variables released in the previous part of this catalog to select objects with severe drops in luminosity, i.e. with the DY-Per-like light curves. DY Per stars are often related to R CrB variables. We detect at least 600 candidates for DY Per stars, mostly among dust enshrouded giants. We notice that our candidate DY Per stars form a continuity with other carbon-rich long-period variables, so it seems that DY Per stars do not constitute a separate group of variable stars.