New R Coronae Borealis and DY Persei Star Candidates and Other Related Objects Found in Photometric Surveys

Volume 42 number 1 (2014)

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Sebastián Otero

AAVSO Headquarters, 49 Bay State Road, Cambridge, MA 02138; address email correspondence to sebastian@aavso.org

Stefan Hümmerich

Stiftstr. 4, Braubach, D-56338, Germany

Klaus Bernhard

Kafkaweg 5, Linz, 4030, Austria

Igor Soszyński

Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland

Abstract

We have carried out a search for new R Coronae Borealis (RCB) variables using the publicly accessible data from various photometric sky surveys and -- whenever available -- AAVSO visual data. Candidates were selected from Tisserand's "Catalogue enriched with R CrB stars" and by a visual inspection of light curves from the ASAS-3, MACHO, NSVS and OGLE surveys. We have identified two new RCB stars, four RCB candidates, and one DY Persei (DYPer) star candidate. Our identification was based mainly on photometric variability, color-color diagrams, and further information drawn from various catalogue sources; spectroscopic classifications were also reported in our analysis whenever available. Additionally, we present a sample of interesting stars which -- although showing similar photometric variability -- can be ruled out as RCB and DYPer stars or have been rejected as such on spectroscopic grounds in recent studies. Although not useful in the investigation of the aforementioned groups of variables, these objects defy an easy classification and might be interesting targets for follow-up studies which we encourage for all stars presented in this paper.