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The 1.17 Day Orbit of the Double-degenerate (DA+DQ) NLTT 16249
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SYSNO ASEP 0388495 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title The 1.17 Day Orbit of the Double-degenerate (DA+DQ) NLTT 16249 Author(s) Vennes, Stephane (ASU-R) ORCID, RID
Kawka, Adela (ASU-R) ORCID, RID
O'Toole, S.J. (AU)
Thorstensen, J.R. (US)Source Title Astrophysical Journal Letters. - : Institute of Physics Publishing - ISSN 2041-8205
Roč. 756, č. 1 (2012), L5/1-L5/4Number of pages 4 s. Language eng - English Country US - United States Keywords close binaries ; white dwarfs ; fundamental parameters Subject RIV BN - Astronomy, Celestial Mechanics, Astrophysics R&D Projects GAP209/10/0967 GA ČR - Czech Science Foundation (CSF) Institutional support ASU-R - RVO:67985815 UT WOS 000308074800005 DOI 10.1088/2041-8205/756/1/L5 Annotation New spectroscopic observations show that the double-degenerate system NLTT 16249 is in a close orbit (a = 5.6 +/- 0.3 R-circle dot) with a period of 1.17 days. The total mass of the system is estimated between 1.47 and 2.04 M-circle dot but it is not expected to merge within a Hubble timescale (t(merge) approximate to 10(11) yr). Vennes & Kawka originally identified the system because of the peculiar composite hydrogen (DA class) and molecular (C-2-DQ class and CN) spectra and the new observations establish this system as the first DA plus DQ close double degenerate. Also, the DQ component was the first of its class to show nitrogen dredged up from the core in its atmosphere. The star may be viewed as the first known DQ descendant of the born-again PG1159 stars. Alternatively, the presence of nitrogen may be the result of past interactions and truncated evolution in a close binary system. Workplace Astronomical Institute Contact Radka Svašková, bibl@asu.cas.cz, Tel.: 323 620 326 Year of Publishing 2013
Number of the records: 1