Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-02-02
Nature 431 (2004) 819
Astronomy and Astrophysics
Astrophysics
Appeared in Nature, 431, 819 (2004)
Scientific paper
10.1038/nature02934
Some main-sequence stars of spectral type A are observed to have a strong (300-30000 G), static, large-scale magnetic field, of a chiefly dipolar shape -- the `Ap stars' (for example Alioth, the fifth star in the Big Dipper). Following their discovery fifty years ago, it was speculated that these fields a remnants of the star's formation, a `fossil' field. Alternatively, they could be generated by a dynamo process in the star's convective core. The dynamo hypothesis has difficulty explaining high field strengths and the lack of a correlation with rotation. The weakness of the fossil-field theory has been the absence of known field configurations stable enough to survive in a star over its lifetime. We demonstrate here the formation of stable magnetic field configurations, with properties agreeing with those observed, by evolution from arbitrary, unstable initial fields. The results are applicable equally to Ap stars, magnetic white dwarfs and some highly magnetised neutron stars known as magnetars. This establishes fossil fields as the natural, unifying explanation for the magnetism of all these stars.
Braithwaite Jonathan
Spruit Hendrik C.
No associations
LandOfFree
A fossil origin for the magnetic fields of A-stars and white dwarfs does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A fossil origin for the magnetic fields of A-stars and white dwarfs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A fossil origin for the magnetic fields of A-stars and white dwarfs will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-60611