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arXiv · 1809.01743

A plethora of new R Coronae Borealis stars discovered from a dedicated spectroscopic follow-up survey

P. Tisserand·G. C. Clayton·M. S. Bessell·D. L. Welch·D. Kamath·P. R. Wood·P. Wils·Ł. Wyrzykowski·P. Mróz·A. Udalski
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Abstract

It is increasingly suspected that the rare R Coronae Borealis (RCB) stars - hydrogen-deficient and carbon-rich supergiant stars - are the products of mergers of CO/He white-dwarf binary systems in the intermediate mass regime ($0.6 15000$ K). Forty of these belong to the Milky Way and five are located in the Magellanic Clouds. We also confirmed that the long lasting candidate KDM 5651 is indeed a new Magellanic RCB star, increasing the total number of Magellanic Cloud RCB stars to 30. We have increased by $\sim$50\% the total number of RCB stars known, now reaching 147. We also include a list of 14 strong RCB candidates, most certainly observed during a dust obscuration phase. From the detection efficiency and success rate so far, we estimate that there should be no more than 500 RCB stars/HdC stars in the Milky Way.

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P. Tisserand, G. C. Clayton, M. S. Bessell, D. L. Welch, D. Kamath, P. R. Wood, P. Wils, Ł. Wyrzykowski, P. Mróz, A. Udalski. 2018-09-05. A plethora of new R Coronae Borealis stars discovered from a dedicated spectroscopic follow-up survey. https://doi.org/10.1051/0004-6361%2F201834410

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