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RR-Lyrae-type pulsations from a 0.26-solar-mass star in a binary system.

التفاصيل البيبلوغرافية
العنوان: RR-Lyrae-type pulsations from a 0.26-solar-mass star in a binary system.
المؤلفون: Pietrzyński G; Departamento de Astronomìa, Universidad de Concepción, Casilla 160-C, Concepciòn, Chile. pietrzyn@astrouw.edu.pl, Thompson IB, Gieren W, Graczyk D, Stępień K, Bono G, Moroni PG, Pilecki B, Udalski A, Soszyński I, Preston GW, Nardetto N, McWilliam A, Roederer IU, Górski M, Konorski P, Storm J
المصدر: Nature [Nature] 2012 Apr 04; Vol. 484 (7392), pp. 75-7. Date of Electronic Publication: 2012 Apr 04.
نوع المنشور: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.
اللغة: English
بيانات الدورية: Publisher: Nature Publishing Group Country of Publication: England NLM ID: 0410462 Publication Model: Electronic Cited Medium: Internet ISSN: 1476-4687 (Electronic) Linking ISSN: 00280836 NLM ISO Abbreviation: Nature Subsets: PubMed not MEDLINE
أسماء مطبوعة: Publication: Basingstoke : Nature Publishing Group
Original Publication: London, Macmillan Journals ltd.
مستخلص: RR Lyrae pulsating stars have been extensively used as tracers of old stellar populations for the purpose of determining the ages of galaxies, and as tools to measure distances to nearby galaxies. There was accordingly considerable interest when the RR Lyrae star OGLE-BLG-RRLYR-02792 (referred to here as RRLYR-02792) was found to be a member of an eclipsing binary system, because the mass of the pulsator (hitherto constrained only by models) could be unambiguously determined. Here we report that RRLYR-02792 has a mass of 0.26 solar masses M[symbol see text] and therefore cannot be a classical RR Lyrae star. Using models, we find that its properties are best explained by the evolution of a close binary system that started with M[symbol see text] and 0.8M[symbol see text]stars orbiting each other with an initial period of 2.9 days. Mass exchange over 5.4 billion years produced the observed system, which is now in a very short-lived phase where the physical properties of the pulsator happen to place it in the same instability strip of the Hertzsprung-Russell diagram as that occupied by RR Lyrae stars. We estimate that only 0.2 per cent of RR Lyrae stars may be contaminated by systems similar to this one, which implies that distances measured with RR Lyrae stars should not be significantly affected by these binary interlopers.
تواريخ الأحداث: Date Created: 20120407 Date Completed: 20120518 Latest Revision: 20120406
رمز التحديث: 20221213
DOI: 10.1038/nature10966
PMID: 22481359
قاعدة البيانات: MEDLINE
الوصف
تدمد:1476-4687
DOI:10.1038/nature10966