University of Washington | Lowell Observatory | 2020 Mar 06
Late last year, news broke that the star Betelgeuse was fading significantly, ultimately dropping to around 40% of its usual brightness. The activity fueled popular speculation that the red supergiant would soon explode as a massive supernova.
But astronomers have more benign theories to explain the star’s dimming behavior. And scientists at the University of Washington and Lowell Observatory believe they have support for one of them: Betelgeuse isn’t dimming because it’s about to explode — it’s just dusty.
In a paper accepted to Astrophysical Journal Letters and published on the preprint site arXiv, Emily Levesque, a UW associate professor of astronomy, and Phillip Massey, an astronomer with Lowell Observatory, report that observations of Betelgeuse taken Feb. 14 at the Flagstaff, Arizona, observatory allowed them to calculate the average surface temperature of the star. They discovered that star is significantly warmer than expected if the recent dimming were caused by a cooling of the star’s surface.
The new calculations lend support to the theory that Betelgeuse — as many red supergiant stars are prone to do — has likely sloughed off some material from its outer layers. ...
Betelgeuse Just Isn't That Cool: Effective Temperature Alone Cannot
Explain the Recent Dimming of Betelgeuse ~ Emily M. Levesque, Philip Massey
- arXiv.org > astro-ph > arXiv:2002.10463 > 24 Feb 2020