Discovery of the most rapidly-rotating, non-degenerate, magnetic massive star by the MiMeS collaboration

TL;DR

This paper reports the discovery of HD 142184 as the fastest-rotating, non-degenerate magnetic star, with a strong magnetic field and a structured magnetosphere, identified through spectropolarimetric observations in the MiMeS survey.

Contribution

It presents the first detection of a rapidly rotating, magnetic B-type star with a detailed magnetic and rotational characterization.

Findings

HD 142184 is the fastest-rotating non-degenerate magnetic star.

It exhibits emission line variability indicating a structured magnetosphere.

The star has a rotational period of 0.50833 days.

Abstract

We discuss the recent detection of a strong, organized magnetic field in the bright, broad-line B2V star, HD 142184, using the ESPaDOnS spectropolarimeter on the CFHT as part of the Magnetism in Massive Stars (MiMeS) survey. We find a rotational period of 0.50833 days, making it the fastest-rotating, non-degenerate magnetic star ever detected. Like the previous rapid-rotation record holder HR 7355 (also discovered by MiMeS: Oksala et al. 2010, Rivinius et al. 2010), this star shows emission line variability that is diagnostic of a structured magnetosphere.