A time-resolved spectroscopic study and modeling of the dwarf nova BV Centauri
Citations Over Time
Abstract
Time-resolved observations of the double-lined, 14 hr 40 min spectroscopic binary BV Centauri are presented. The spectrum shows hydrogen emission lines from an accretion disk around the white dwarf primary and absorption lines from a late-type star of spectral class G5-8 IV-V. The reduction technique is discussed and yields the velocity amplitudes Kabs = 128 ± 3 Kems = 139 ± 9 km s-1, with a derived orbital period, P = 0d.611179. The velocity amplitudes are significantly different from previously published results. Results of stellar evolution computations are presented to better define the nature of the presumably evolved secondary in this long period system. Masses of the mass-losing secondary and accreting white dwarf are: Msec = 0.9 ± 0.1 Msun and MWD = 0.83 ± 0.1 Msun. A mass transfer rate of 5.0 ± 2.0 × 10-10 Msun yr-1 is determined from orbital and stellar evolution considerations in conjunction with observed relative component brightnesses. The secondary star probably has a small He core and has a radius at least 50% larger than that for a zero-age main-sequence star of the same mass.