Abstract
EC13471-1258 is a detached eclipsing binary with Porb = 3h37m, comprising a DA white dwarf and a dMe dwarf. Total eclipses of the white dwarf lasting 14 min, and a large amplitude ellipsoidal variation are seen in the light curve. Flares from the dMe star occur regularly. Each star contributes roughly equal amounts of light at 5500 Ang. HST STIS spectra show strong Ly alpha with weak metal lines, and yield Teff = 14220 K, log g = 8.34, Z = 1/30th solar, K = 138 km/s and V sin i = 400 km/s for the white dwarf. Optical spectra yield the spectral type (M3.5-4.0), Teff = 3100 K, Z = solar, K = 266 km/s and V sin i = 140 km/s for the dMe star. The H alpha emission line comprises 2 or more components and implies that very weak mass transfer is occurring. The dynamical solution also implies that the dMe star just fills its Roche lobe. Accurate masses and radii for each star were derived: the dMe values favour the Clemens et al. (1998) mass-radius relation. The large rotational velocity of the white dwarf (400 km/s) suggests that the system has transferred mass in the past so that it is presently a hibernating cataclysmic variable. The metallicity contrast between the component stars provides an opportunity for tests of diffusion theory.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
