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arXiv · 2006.09409

Betelgeuse fainter in the sub-millimetre too: an analysis of JCMT and APEX monitoring during the recent optical minimum

Thavisha E. Dharmawardena·Steve Mairs·Peter Scicluna·Graham Bell·Iain McDonald·Karl Menten·Axel Weiss·Albert Zijlstra
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Abstract

Betelgeuse is the nearest Red Supergiant star and it underwent an unusually deep minimum at optical wavelengths during its most recent pulsation cycle. We present submillimetre observations taken by the James Clerk Maxwell Telescope and Atacama Pathfinder Experiment over a time span of 13 years including the optical dimming. We find that Betelgeuse has also dimmed by \sim20\% at these longer wavelengths during this optical minimum. Using radiative-transfer models, we show that this is likely due to changes in the photosphere (luminosity) of the star as opposed to the surrounding dust as was previously suggested in the literature.

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Thavisha E. Dharmawardena, Steve Mairs, Peter Scicluna, Graham Bell, Iain McDonald, Karl Menten, Axel Weiss, Albert Zijlstra. 2020-06-16. Betelgeuse fainter in the sub-millimetre too: an analysis of JCMT and APEX monitoring during the recent optical minimum. https://doi.org/10.3847/2041-8213/ab9ca6

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