Bibcode
Casares, J.; Mouchet, M.; Martinez-Pais, I. G.; Harlaftis, E. T.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 282, Issue 1, pp. 182-190.
Advertised on:
9
1996
Citations
55
Refereed citations
48
Description
We report intermediate resolution spectroscopy (50 km/s) of the magnetic
Cataclysmic Variable AE Aqr performed as part of the World Astronomy
Days (WAD) campaign. Our analysis of the absorption features supports a
K4 classification for the companion star, which contributes more than
95% of the total flux in the range 600-700 nm. We find that the
companion star fills its Roche lobe since we detect a 10% modulation in
the rotational broadening (V sin i) of the absorption fines, due to the
changing geometry. Model fitting to the V sin i(phi) curve enables us to
measure directly the system inclination (i = 58 +/- 6 deg) and the
gravity darkening coefficient (beta = 0.08 +/- 0.01). Improved orbital
parameters are also presented, including an updated mass ratio (q =
K1/K2 = 0.630 +/- 0.012) based upon our
K2 value and the spin-pulse delay. An independent
determination of q is also provided by correcting the phase-averaged V
sin i for non-spherical effects. The need for these two values to agree
constrain the limb-darkening coefficient to be epsilon approximately
equal to 0.40 (for beta = 0.08). The component masses derived from our
values of K2, q and i are M1 = 0.79 +/- 0.16 solar
mass units and M2 = 0.50 +/- 0.10 solar mass units. In
addition, we do not see spectral evidence of irradiation effects.