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arXiv · 1407.8505

$\xi^1$ CMa: An Extremely Slowly Rotating Magnetic B0.7 IV Star

Matt Shultz·Gregg Wade·Thomas Rivinius·Wagner Marcolino·Huib Henrichs·Jason Grunhut·the MiMeS Collaboration
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Abstract

We present our analysis of 6 years of ESPaDOnS spectropolarimetry of the magnetic $\beta$ Cep star $\xi^1$ CMa (B0.7 IV). This high-precision magnetometry is consistent with a rotational period $P{\rm rot} >$ 40 yr. Absorption line profiles can be reproduced with a non-rotating model. We constrain $R_*$, $L_*$, and the stellar age via a Baade-Wesselink analysis. Spindown due to angular momentum loss via the magnetosphere predicts an extremely long rotational period if the magnetic dipole $B_{\rm d} > 6$ kG, a strength also inferred by the best-fit sinusoids to the longitudinal magnetic field measurements $B_{\rm Z}$ when phased with a 60-year $P_{\rm rot}$.

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Matt Shultz, Gregg Wade, Thomas Rivinius, Wagner Marcolino, Huib Henrichs, Jason Grunhut, the MiMeS Collaboration. 2014-07-31. $\xi^1$ CMa: An Extremely Slowly Rotating Magnetic B0.7 IV Star. https://doi.org/10.1017/s1743921314007261

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