Dynamo Generation of Magnetic Fields in White Dwarfs

Abstract

view Abstract Citations (32) References (33) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Dynamo Generation of Magnetic Fields in White Dwarfs Thomas, John H. ; Markiel, J. Andrew ; van Horn, H. M. Abstract Our earlier analysis of αω dynamos in white dwarfs, aimed specifically at explaining the time-varying magnetic field in the DBV white dwarf GD 358 discovered by Winget et al., is improved and extended to a broader range of white dwarf types. Our nonlinear, local dynamo equations, based on those of Robinson and Durney, are modified to account for new evidence concerning the Sun's αω dynamo. We calculate dynamo magnetic fields for both He-envelope (DB) and H-envelope (DA) white dwarfs, for a range of values of mass, luminosity, rotation rate, and amount of differential rotation, and for convective envelopes computed with different formulations of convection theory. The results strengthen the case for dynamo generation of the magnetic field observed in GD 358. The results also show that dynamo generation of magnetic fields could occur in many DB and DA white dwarfs, including other pulsating DBV stars (besides GD 358) and DAV stars for which the magnetic fields may be detectable by asteroseismological techniques. Publication: The Astrophysical Journal Pub Date: November 1995 DOI: 10.1086/176400 Bibcode: 1995ApJ...453..403T Keywords: MAGNETOHYDRODYNAMICS: MHD; STARS: INDIVIDUAL ALPHANUMERIC: GD 358; STARS: MAGNETIC FIELDS; STARS: WHITE DWARFS full text sources ADS | data products SIMBAD (1)