The donor star radial velocity curve in the cataclysmic variable GY Cnc confirms white dwarf eclipse modelling mass

Littlefair, S. P.; Rodríguez-Gil, Pablo; Marsh, T. R.; Parsons, S. G.; Dhillon, V. S.
Referencia bibliográfica

Monthly Notices of the Royal Astronomical Society

Fecha de publicación:
1
2024
Número de autores
5
Número de autores del IAC
1
Número de citas
1
Número de citas referidas
1
Descripción
A large number of white dwarf and donor masses in cataclysmic variables have been found via modelling the primary eclipse, a method that relies on untested assumptions. Recent measurements of the mass of the white dwarf in the cataclysmic variable GY Cnc, obtained via modelling its ultraviolet spectrum, conflict with the mass obtained via modelling the eclipse light curve. Here we measure the radial velocity of the absorption lines from the donor star in GY Cnc to be Kabs = 280 ± 2 km s-1, in excellent agreement with the prediction based on the masses derived from modelling the eclipse light curve. It is possible that the white dwarf mass derived from the ultraviolet spectrum of GY Cnc is affected by the difficulty of disentangling the white dwarf spectrum from the accretion disc spectrum.