Bibcode
Casares, J.; Martínez-Pais, I. G.; Rodríguez-Gil, P.
Referencia bibliográfica
Monthly Notices of the Royal Astronomical Society, Volume 399, Issue 3, pp. 1534-1538.
Fecha de publicación:
11
2009
Número de citas
8
Número de citas referidas
7
Descripción
Intermediate-resolution (0.5-1 Å) optical spectroscopy of the
cataclysmic variable (CV) SY Cnc reveals the spectrum of the donor star.
Our data enable us to resolve the orbital motion of the donor and
provide a new orbital solution, binary mass ratio and spectral
classification. We find that the donor star has spectral-type G8 +/- 2 V
and orbits the white dwarf with P = 0.3823753 +/- 0.0000003 d,
K2 = 88.0 +/- 2.9 kms-1 and V sini = 75.5 +/- 6.5
kms-1. Our values are significantly different from previous
works and lead to q = M2/M1 = 1.18 +/- 0.14. This
is one of the highest mass ratios known in a CV and is very robust,
because it is based on resolving the rotational broadening over a large
number of metallic absorption lines. The donor could be a slightly
evolved main sequence or descendant from a massive star which underwent
an episode of thermal time-scale mass transfer.