Properties of a volume-limited sample of magnetic Ap/Bp stars

Abstract

This paper describes a study to deduce fundamental parameters and magnetic field characteristics for all magnetic Ap/Bp stars with in a 100 parsec heliocentric radius volume. This study has allowed for the first time the determination of an effectively unbiased magnetic field distribution of a sample of intermediate mass stars. From published catalogues and other literature sources, we have identified 57 bone fide magnetic A and B stars in the volume, corresponding to 1.7% of all intermediate mass stars within 100 parsec of the Sun. The masses of Ap stars range from 1.5 to 6 solar masses, with the peak of the mass incidence distribution between 3.3 and 3.6 solar masses. Observations of 30 of the Ap/Bp stars were obtained using the MuSiCoS spectropolarimeter at the Telescope Bernard Lyot at Pic du Midi Observatory. These observations will be used to refine periods, and determine magnetic field strength and geometry.