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dc.contributor.authorTisserand, P.
dc.contributor.authorClayton, G.
dc.contributor.authorKilkenny, David
dc.contributor.authorWelch, D. L.
dc.contributor.authorWyrzykowsk, L.
dc.contributor.authorPilecki, B.
dc.date.accessioned2017-07-14T08:54:12Z
dc.date.available2017-07-14T08:54:12Z
dc.date.issued2013
dc.identifier.citationTisserand, P. et al. (2013). The ongoing pursuit of R Coronae Borealis stars: the ASAS-3 survey strikes again. Astronomy & Astrophysics, 551 (A77): 1-22en_US
dc.identifier.issn0004-6361
dc.identifier.urihttp://hdl.handle.net/10566/3081
dc.description.abstractCONTEXT: R Coronae Borealis stars( RCBs) are rare, hydrogen-deficient, carbon rich super giant variable stars that are likely the evolved merger products of pairs of CO and He white dwarfs. Only 55 RCB stars have been found in our galaxy and their distribution on the sky is weighted heavily by microlensing survey field positions. A less biased wide-area survey would enable us to test competing evolutionary scenarios, understand the population or populations that produce RCBs, and constrain their formation rate. AIMS: The ASAS-3 survey monitored the sky south of declination +28deg between 2000 and 2010 to a limiting magnitude of V = 14. We searched ASAS-3 for RCB variables using several different methods to ensure that the probability of RCB detection was as high as possible and to reduce selection biases based on luminosity, temperature, dust production activity and shell brightness. METHODS: Candidates whose light curves were visually inspected were pre-selected based on their infrared (IR) excesses due to warm dust in their circumstellar shells using the WISE and/or 2MASS catalogues. Criteria on light curve variability were also applied when necessary to minimise the number of objects. Initially, we searched for RCB stars among the ASAS-3 ACVS1.1 variable star catalogue, then among the entire ASAS-3 south source catalogue, and finally directly interrogated the light curve database for objects that were not catalogued in either of those. We then acquired spectra of 104 stars to determine their real nature using the SSO/WiFeS spectrograph. RESULTS: We report 21 newly discovered RCB stars and 2 new DY Per stars. Two previously suspected RCB candidates were also spectroscopically confirmed. Our methods allowed us to extend our detection efficiency to fainter magnitudes that would not have been easily accessible to discovery techniques based onlight curve variability. The overall detection efficiencyis about 90% for RCBs with maximum light brighter than V ∼13. CONCLUSIONS: With these new discoveries, 76 RCBs are now known in our Galaxy and 22 in the Magellanic Clouds. This growing sample is of great value to constrain the peculiar and disparate atmosphere composition of RCBs. Most importantly, we show that the spatial distribution and apparent magnitudes of Galactic RCB stars is consistent with RCBs being part of the Galactic bulge population.en_US
dc.language.isoenen_US
dc.publisherEDP Sciencesen_US
dc.rightsPublisher retains copyright. Authors may archive the published version in their institutional repository.
dc.source.urihttp://dx.doi.org/10.1051/0004-6361/201220713
dc.subjectStarsen_US
dc.subjectAGB and post AGB supergiantsen_US
dc.subjectLate-type starsen_US
dc.subjectVariablesen_US
dc.subjectGeneralen_US
dc.titleThe ongoing pursuit of R Coronae Borealis stars: the ASAS-3 survey strikes againen_US
dc.typeArticleen_US
dc.description.accreditationDepartment of HE and Training approved list


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