https://www.space.com/is-betelgeuse-going-supernova Morgan MacLeod, a postdoc at Harvard University and co-autho
MacLeod = Morgan MacLeod
Montargès = Miguel Montarges
"The helium-burning phase is several hundred thousand years long," Miguel Montargès, a post-doctoral fellow at the Laboratory of Space Studies and Instrumentation in Astrophysics at the Paris Observatory and Betelgeuse expert, told Space.com.
"Then you have the next phase that lasts like 10,000 years, then thousands of years, and then it's a century, and the final one is only some days and hours just before the explosion."
Like MacLeod, Montargès thinks that Betelgeuse still has many thousands of years of life ahead of it and is rather unconcerned by the recent unexpected brightening. In fact, the star has been this bright previously, he said, albeit only for brief periods of time.
"If we compare the current brightening to the Great Dimming, it's really quite negligible," Montargès said. "During the Great Dimming, the magnitude [a measure of a star's brightness that is logarithmic and inversely proportional to the visible brightness] went from 0.8 down to 1.75. The usual peak brightness, on the other hand, is about 0.3, and now we are only at about 0.1."