uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Oxygen Isotopic Ratios in Cool R Coronae Borealis Stars
Show others and affiliations
2010 (English)In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 714, no 1, 144-154 p.Article in journal (Refereed) Published
Abstract [en]

We investigate the relationship between R Coronae Borealis (RCB) stars and hydrogen-deficient carbon (HdC) stars by measuring precise O-16/O-18 ratios for five cool RCB stars. The O-16/O-18 ratios are derived by spectrum synthesis from high-resolution (R similar to 50,000) K-band spectra. Lower limits to the O-16/O-17 and N-14/N-15 ratios as well as Na and S abundances (when possible) are also given. RCB stars in our sample generally display less O-18 than HdC stars-the derived O-16/O-18 ratios range from 3 to 20. The only exception is the RCB star WX CrA, which seems to be an HdC-like star with O-16/O-18 = 0.3. Our result of a higher O-16/O-18 ratio for the RCB stars must be accounted for by a theory of the formation and evolution of HdC and RCB stars. We speculate that a late dredge-up of products of He burning, principally C-12 and O-16, may convert an O-18-rich HdC star into an O-18-poor RCB star as the H-deficient star begins its final evolution from a cool supergiant to the top of the white dwarf cooling track.

Place, publisher, year, edition, pages
2010. Vol. 714, no 1, 144-154 p.
Keyword [en]
infrared: stars, stars: abundances, stars: atmospheres, stars: chemically peculiar, white dwarfs
National Category
Astronomy, Astrophysics and Cosmology
URN: urn:nbn:se:uu:diva-136984DOI: 10.1088/0004-637X/714/1/144ISI: 000276701000012OAI: oai:DiVA.org:uu-136984DiVA: diva2:377796
Available from: 2010-12-14 Created: 2010-12-14 Last updated: 2010-12-14Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text
By organisation
Department of Physics and Astronomy
In the same journal
Astrophysical Journal
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 147 hits
ReferencesLink to record
Permanent link

Direct link