HD 34382: A Photometrically Identified Candidate Centrifugal Magnetosphere Star

Abstract We identify the chemically peculiar B8/9V star HD 34382 as a candidate member of the rare class of rapidly rotating magnetic B stars. TESS photometry shows eclipses and smooth sinusoidal variability with a period of 2.46 days. We supplement this with Keck/HIRES spectroscopy, which shows that this is a Bp star. The data suggest that the star’s photometric variability results from a combination of chemical surface spots and eclipses by dense, magnetically confined plasma clouds, making this star’s behavior analogous to that of stars like σ Ori E. If the star’s magnetic nature is confirmed through spectropolarimetry, then HD 34382 may possess the longest rotational period known for such stars with photometrically detectable centrifugal magnetospheres. Furthermore, the star’s low temperature could make HD 34382 the coolest star of its class in which such detected centrifugal magnetosphere derived photometric variability has been observed, pending such magnetic confirmation.