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arXiv · 1610.05625

Understanding the photometric variability of ζ Ori Aa

B. Buysschaert·C. Neiner·T. Ramiaramanantsoa·N. D. Richardson·A. David-Uraz·A. F. J. Moffat
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Abstract

We studied the variability of the magnetic O-type supergiant $ζ$ Ori Aa using multi-colour BRITE photometry. We confirmed the known rotation frequency $f_{\rm rot} = 0.15 \pm 0.02$ c/d, and detected some of its higher harmonics, of which $4f_{\rm rot}$ is compatible with the known DAC recurrence timescale. Thanks to simultaneous high-resolution CHIRON spectroscopy, we could identify another frequency $f_{\rm env} = 0.10 \pm 0.02$ c/d, caused by the circumstellar environment. Variations in the circumstellar environment are believed to cause the observed difference between the BRITE lightcurves.

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B. Buysschaert, C. Neiner, T. Ramiaramanantsoa, N. D. Richardson, A. David-Uraz, A. F. J. Moffat. 2016-10-18. Understanding the photometric variability of ζ Ori Aa. https://arxiv.org/abs/1610.05625

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