A coordinated campaign on the intermediate polar AE AQR - I. The system parameters
Abstract
We report intermediate-resolution spectroscopy (50 km s^-1) 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 >=95 per cent 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 per cent modulation in the rotational broadening (V sin i) of the absorption lines, arising from 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=K_1/K_2=0.630+/-0. 012) based upon our K_2 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 constrains the limb-darkening coefficient to be epsilon~=0.40 (for beta=0.08). The component masses derived from our values of K_2, q and i are M_1=0.79+/-0.16 M_ and M_2=0.50+/-0.10 M_. In addition, we do not see spectral evidence of irradiation effects.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- September 1996
- DOI:
- 10.1093/mnras/282.1.182
- Bibcode:
- 1996MNRAS.282..182C
- Keywords:
-
- ACCRETION;
- ACCRETION DISCS;
- BINARIES: CLOSE;
- BINARIES: SPECTROSCOPIC;
- STARS: INDIVIDUAL: AE AQR;
- NOVAE;
- CATACLYSMIC VARIABLES;
- Cataclysmic Variables;
- Stellar Mass Accretion;
- Spectrum Analysis;
- Stellar Spectra;
- Stellar Mass;
- Absorption Spectra;
- Line Spectra;
- Accretion Disks;
- Classifications;
- Flux (Rate);
- Astronomy