Počet záznamů: 1

The double degenerate system NLTT 11748

  1. 1.
    0354849 - ASU-R 2011 RIV FR eng J - Článek v odborném periodiku
    Kawka, Adela - Vennes, Stephane - Vaccaro, T.R.
    The double degenerate system NLTT 11748.
    Astronomy & Astrophysics. Roč. 516, Jun-Jul (2010), L7/1-L7/4 ISSN 0004-6361
    Grant CEP: GA AV ČR(CZ) IAA300030908; GA ČR GAP209/10/0967
    Grant ostatní: GA AV ČR(CZ) IAA301630901
    Výzkumný záměr: CEZ:AV0Z10030501
    Klíčová slova: close binaries * white dwarfs
    Kód oboru RIV: BN - Astronomie a nebeská mechanika, astrofyzika
    Impakt faktor: 4.410, rok: 2010

    We show that the extremely low-mass white dwarf NLTT 11748 (0.17 of solar mass) is in a close binary with a fainter companion. We obtained a series of radial velocity measurements of the low-mass white dwarf using the Halpha core and determined an orbital period of 5.64 h. The velocity semi-amplitude (K = 274.8 km/s) and orbital period imply that it is a degenerate star, and that the minimum mass for the companion is 0.75 of solar mass (assuming a mass of 0.167 of solar mass for the primary). Our analysis of Balmer line profiles shows that a 0.75 of solar mass white dwarf companion does not contribute more than 2% or 5% of the flux (V-band) for helium-or hydrogen-rich surfaces, respectively. The kinematics of the system suggest that it belongs to the Galactic halo.
    Trvalý link: http://hdl.handle.net/11104/0193761