TY - JOUR
AU1 - Shultz, M
AU2 - Kochukhov, O
AU3 - Wade, G A
AU4 - Rivinius, Th
AB - We report the latest set of spectropolarimetric observations of the magnetic β Cep star ξ1 CMa. The new observations confirm the long-period model of Shultz et al. (2017), who proposed a rotational period of about 30 years and predicted that in 2018 the star should pass through a magnetic null. In perfect agreement with this projection, all longitudinal magnetic field ⟨Bz⟩ measurements are close to 0 G. Remarkably, individual Stokes V profiles all display a crossover signature, which is consistent with ⟨Bz⟩ ∼ 0 but is not expected when v sin i ∼ 0. The crossover signatures furthermore exhibit pulsationally modulated amplitude and sign variations. We show that these unexpected phenomena can all be explained by a ‘radial crossover’ effect related to the star’s radial pulsations, together with an important deviation of the global field topology from a purely dipolar structure, that we explore via a dipole+quadrupole configuration as the simplest non-dipolar field.
TI - The pulsationally modulated radial crossover signature of the slowly rotating magnetic B-type star ξ1 CMa★
JF - Monthly Notices of the Royal Astronomical Society Letters
DO - 10.1093/mnrasl/sly070
DA - 2018-04-24
UR - https://www.deepdyve.com/lp/oxford-university-press/the-pulsationally-modulated-radial-crossover-signature-of-the-slowly-gQVg7hheM1
SP - L39
EP - L43
VL - 478
IS - 1
DP - DeepDyve
ER -