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arXiv · 2004.09698

MOBSTER -- IV. Detection of a new magnetic B-type star from follow-up spectropolarimetric observations of photometrically selected candidates

A. David-Uraz·M. E. Shultz·V. Petit·D. M. Bowman·C. Erba·R. A. Fine·C. Neiner·H. Pablo·J. Sikora·A. ud-Doula·G. A. Wade
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Abstract

In this paper, we present results from the spectropolarimetric follow-up of photometrically selected candidate magnetic B stars from the MOBSTER project. Out of four observed targets, one (HD 38170) is found to host a detectable surface magnetic field, with a maximum longitudinal field measurement of 105$\pm$14 G. This star is chemically peculiar and classified as an $\alpha^2$ CVn variable. Its detection validates the use of TESS to perform a photometric selection of magnetic candidates. Furthermore, upper limits on the strength of a putative dipolar magnetic field are derived for the remaining three stars, and we report the discovery of a previously unknown spectroscopic binary system, HD 25709. Finally, we use our non-detections as case studies to further inform the criteria to be used for the selection of a larger sample of stars to be followed up using high-resolution spectropolarimetry.

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A. David-Uraz, M. E. Shultz, V. Petit, D. M. Bowman, C. Erba, R. A. Fine, C. Neiner, H. Pablo, J. Sikora, A. ud-Doula, G. A. Wade. 2020-04-21. MOBSTER -- IV. Detection of a new magnetic B-type star from follow-up spectropolarimetric observations of photometrically selected candidates. https://doi.org/10.1093/mnras/stab899

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