Can the rapid braking of the white dwarf in AE Aquarii be explained in terms of the gravitational wave emitter mechanism?

Abstract

The spin-down power of the white dwarf in the close binary AE Aquarii significantly exceeds the bolometric luminosity of the system. The interpretation of this phenomenon in terms of the gravitational-wave emitter mechanism has been recently suggested by Choi & Yi. The basic assumption of their interpretation is that the spatially limited blobs or mounds of the mass δm ~ 10^{-3} M_sun, are present at the magnetic poles of the white dwarf. We show that the mounds of this mass can be confined by the magnetic field of the white dwarf only if the dipole magnetic moment of the star exceeds 4x10^{37} G cm^3. Under these conditions, however, the magnetodipole losses of the white dwarf would exceed the evaluated spin-down power 6 orders of magnitude. On this basis we discard a possibility that the observed rapid braking of the white dwarf in AE Aquarii can be explained in terms of the mechanism proposed by Choi & Yi.