Meanwhile, up in Orion’s left armpit, Betelgeuse was freaking out.
Last October the red supergiant, the 10th brightest star in the night sky, began to dim. It continued to fade through mid-February, dropping in apparent magnitude (how bright a celestial object appears to observers on Earth) of 0.5 to 1.7, less than half its usual twinkliness.
Some speculated that the dimming might forebode the end astronomers have long known was in store for Betelgeuse: a supernova. As a supergiant star expends the hydrogen that fires its thermonuclear furnace, fusing it into heavier and heavier elements, its core becomes denser and denser until it collapses under its own gravity and releases an absurd amount of energy. With Betelgeuse acting erratically, the stargazing world held its breath and wondered: “Could this be the Big One?”
“It was incredible,” Douglas Leonard, an astronomy professor at San Diego State University, said of the dimming, which was plainly visible to the naked eye, “unprecedented.”
When will Betelgeuse explode? Leonard will discuss that subject as part of Wyoming Stargazing’s “World Above the Tetons” Speaker Series tonight.
The virtual presentation is scheduled via Zoom videoconferencing at 7:30 p.m. Saturday, May 23. Cost is $20 for adults, free for students and children.
For more information, visit WyomingStargazing.org.