Oxygen Isotopic Ratios In Cool R Coronae Borealis Stars
dc.contributor.utaustinauthor | Lambert, David L. | en_US |
dc.creator | Garcia-Hernandez, D. Anibal | en_US |
dc.creator | Lambert, David L. | en_US |
dc.creator | Rao, N. Kameswara | en_US |
dc.creator | Hinkle, Ken. H. | en_US |
dc.creator | Eriksson, Kiell | en_US |
dc.date.accessioned | 2016-04-28T19:33:55Z | |
dc.date.available | 2016-04-28T19:33:55Z | |
dc.date.issued | 2010-05 | en |
dc.description.abstract | We investigate the relationship between R Coronae Borealis (RCB) stars and hydrogen-deficient carbon (HdC) stars by measuring precise (16)O/(18)O ratios for five cool RCB stars. The (16)O/(18)O ratios are derived by spectrum synthesis from high-resolution (R similar to 50,000) K-band spectra. Lower limits to the (16)O/(17)O and (14)N/(15)N ratios as well as Na and S abundances (when possible) are also given. RCB stars in our sample generally display less (18)O than HdC stars-the derived (16)O/(18)O ratios range from 3 to 20. The only exception is the RCB star WX CrA, which seems to be an HdC-like star with (16)O/(18)O = 0.3. Our result of a higher (16)O/(18)O 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 (12)C and (16)O, may convert an (18)O-rich HdC star into an (18)O-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. | en_US |
dc.description.department | McDonald Observatory | en_US |
dc.description.sponsorship | Spanish Ministry of Science and Innovation (MICINN) AYA-2007-64748 | en_US |
dc.description.sponsorship | Robert A. Welch Foundation of Houston, Texas F-634 | en_US |
dc.description.sponsorship | Swedish Research Council | en_US |
dc.identifier | doi:10.15781/T23R5G | |
dc.identifier.Filename | 2010_05_oxygenisotopic.pdf | en_US |
dc.identifier.citation | Garcia-Hernandez, D. Anibal, David L. Lambert, N. Kameswara Rao, Ken H. Hinkle, and Kjell Eriksson. "Oxygen isotopic ratios in cool R Coronae Borealis stars." The Astrophysical Journal, Vol. 714, No. 1 (May., 2010): 144. | en_US |
dc.identifier.doi | 10.1088/0004-637x/714/1/144 | en_US |
dc.identifier.issn | 0004-637X | en_US |
dc.identifier.uri | http://hdl.handle.net/2152/34756 | |
dc.language.iso | English | en_US |
dc.relation.ispartof | en_US | |
dc.relation.ispartofserial | Astrophysical Journal | en_US |
dc.rights | Administrative deposit of works to Texas ScholarWorks: This works author(s) is or was a University faculty member, student or staff member; this article is already available through open access or the publisher allows a PDF version of the article to be freely posted online. The library makes the deposit as a matter of fair use (for scholarly, educational, and research purposes), and to preserve the work and further secure public access to the works of the University. | en_US |
dc.rights.restriction | Open | en_US |
dc.subject | infrared: stars | en_US |
dc.subject | stars: abundances | en_US |
dc.subject | stars: atmospheres | en_US |
dc.subject | stars: | en_US |
dc.subject | chemically peculiar | en_US |
dc.subject | white dwarfs | en_US |
dc.subject | hydrogen-deficient carbon | en_US |
dc.subject | extreme helium stars | en_US |
dc.subject | white-dwarfs | en_US |
dc.subject | evolution | en_US |
dc.subject | abundances | en_US |
dc.subject | supernovae | en_US |
dc.subject | o-18 | en_US |
dc.subject | astronomy & astrophysics | en_US |
dc.title | Oxygen Isotopic Ratios In Cool R Coronae Borealis Stars | en_US |
dc.type | Article | en_US |