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

Research output: Contribution to journalArticlepeer-review

  • External authors:
  • Thavisha E. Dharmawardena
  • Steve Mairs
  • Peter Scicluna
  • Graham Bell
  • Karl Menten
  • Alex Weiss


Betelgeuse, the nearest Red Supergiant star to us 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 ∼ 20% 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.

Bibliographical metadata

Original languageEnglish
JournalThe Astrophysical Journal Letters
Publication statusAccepted/In press - 14 Jun 2020