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arXiv · 1701.00733

Fast spectral variations of OBA stars

A. F. Kholtygin·S. Hubrig·V. V. Dushin·S. Fabrika·A. Valeev·M. Schoeller·A. E. Kostenkov
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Abstract

Our search for magnetic fields in selected OBA stars using FOcal Reducer low dispersion Spectrographs FORS 1 and FORS 2 in spectropolarimetric mode revealed the presence of strong line profile variations (LPV) in spectra of magnetic OBA stars. More specifically, we detected moderate line profile variations of selected lines on a time scale of minutes in FORS 2 spectra of the A0 supergiant HD 92207 (Hubrig et al. 2014). Recently, we investigated the variability of line profiles of selected OBA stars with the multi-mode focal reducer SCORPIO at the 6-meter BTA telescope. We discovered regular variations of H and He lines in the spectra of the O-type star HD 93521 (O9.5III) with periods ~4-5 and ~32-36 minutes. The possible origin of short time-scale spectral variations is discussed.

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A. F. Kholtygin, S. Hubrig, V. V. Dushin, S. Fabrika, A. Valeev, M. Schoeller, A. E. Kostenkov. 2017-01-03. Fast spectral variations of OBA stars. https://arxiv.org/abs/1701.00733

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