Magnetic field geometries of two slowly rotating Ap/Bp stars: HD 12288 and HD 14437
G.A. Wade 1,
D. Kudryavtsev 2,
I.I. Romanyuk 2,
J.D. Landstreet 3 and
G. Mathys 4
Received 20 December 1999 / Accepted 20 January 2000
In this paper we report magnetic field models and basic physical parameters for the slowly rotating Ap/Bp stars HD 12288 and HD 14437.
Using new and previously published mean longitudinal magnetic field, mean magnetic field modulus, and HIPPARCOS photometric measurements, we have inferred the rotational periods of both stars (HD 12288: ; HD 14437: ). From the magnetic measurements we have determined the best-fit decentred magnetic dipole configurations. For HD 12288, we find that the field geometry is consistent with a centred dipole, while for HD 14437 a large decentring parameter is inferred. Both stars show one angle in the ambiguous couplet which is smaller than about . This is consistent with the observation of Landstreet & Mathys (2000), who point out that almost all magnetic Ap stars with periods longer than about 30 days exhibit magnetic fields aligned with their rotational axis.
Key words: polarization stars: chemically peculiar stars: evolution stars: individual: HD 12288 stars: individual: HD 14437 stars: magnetic fields
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© European Southern Observatory (ESO) 2000
Online publication: March 21, 2000