Article

A ZZCeti white dwarf in SDSSJ133941.11+484727.5

Monthly Notices of the Royal Astronomical Society (Impact Factor: 5.52). 01/2006; DOI: 10.1111/j.1365-2966.2005.09781.x
Source: OAI

ABSTRACT We present time-resolved spectroscopy and photometry of the cataclysmic variable (CV) SDSSJ133941.11+484727.5 (SDSS1339) which has been discovered in the Sloan Digital Sky Survey (SDSS) Data Release 4. The orbital period determined from radial velocity studies is 82.524(24)min, close to the observed period minimum. The optical spectrum of SDSS1339 is dominated to 90 per cent by emission from the white dwarf (WD). The spectrum can be successfully reproduced by a three-component model (white dwarf, disc, secondary) with TWD=12500K for a fixed logg= 8.0, d= 170pc, and a spectral type of the secondary later than M8. The mass-transfer rate corresponding to the optical luminosity of the accretion disc is very low, ~= 1.7 × 10-13Msolaryr-1. Optical photometry reveals a coherent variability at 641s with an amplitude of 0.025mag, which we interpret as non-radial pulsations of the white dwarf. In addition, a long-period photometric variation with a period of either 320 or 344min and an amplitude of 0.025mag is detected, which bears no apparent relation with the orbital period of the system. Similar long-period photometric signals have been found in the CVs SDSSJ123813.73-033933.0, SDSSJ204817.85-061044.8, GWLib and FSAur, but so far no working model for this behaviour is available.

0 Bookmarks
 · 
77 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The fastest pulsar and the slowest nova; the oldest galaxies and the youngest stars; the weirdest life forms and the commonest dwarfs; the highest energy particles and the lowest energy photons. These were some of the extremes of Astrophysics 2006. We attempt also to bring you updates on things of which there is currently only one (habitable planets, the Sun, and the universe) and others of which there are always many, like meteors and molecules, black holes and binaries. Comment: 244 pages, no figures
    Space Science Reviews 05/2007; · 5.52 Impact Factor