The discovery of a brake on the white dwarf in AE Aquarii.
Abstract
We report the discovery of a rapid spindown of the 33-s rotation period of the white dwarf in AE Aqr at a steady rate of 5.64 × 10-14 s s-1 over a baseline of at least 14.5 yr. The newly derived orbital period by Welsh, Home & Gomer is confirmed, and it is shown that the secondary star's absorption-line radial velocities provide the correct phasing for the 33-s oscillations if they originate at the white dwarf. The amplitude of the pulse-timing delays, αwdsin i=2.04s, yields a white dwarf mass of between 0.9 and 1.0 Msun. The spindown power of the white dwarf is --IΩΩdot=6 × 1033 I50 erg s-1, which exceeds the accretion luminosity of AE Aqr by a factor of ∼120. A significant fraction of --IΩΩdot may be converted to the acceleration of particles as in a pulsar, which may explain the observed radio synchrotron emission and the reported γ-ray emission. We also give evidence that the secondary lies above the main sequence since the secondary mass inferred from the mainsequence mass-radius relationship is too large.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- April 1994
- DOI:
- 10.1093/mnras/267.3.577
- Bibcode:
- 1994MNRAS.267..577D
- Keywords:
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- binaries: close - stars: individual: AE Aqr - novae;
- cataclysmic variables - stars: oscillations - stars: rotation - white dwarfs