The bizarre dimming of bright star Betelgeuse caused by giant stellar eruption

Betelgeuse’s odd recent dimming was caused by a huge cloud of material that the supergiant star blasted into space, a new study suggests. The bright star Betelgeuse, which forms the shoulder of the constellation Orion (The Hunter), is about 11 times more massive than the sun but 900 times more voluminous. That bloated condition shows that Betelgeuse is near death, which will come in the form of a violent supernova explosion. In the fall of 2019, Betelgeuse began dimming significantly, losing about two-thirds of its brightness by February. This dramatic dip spurred speculation that the star’s demise may have been imminent — perhaps just weeks away. (From our perspective, anyway; Betelgeuse lies about 500 light-years from Earth, so everything we’re seeing with the star today happened centuries ago.)

But the dramatic sky show didn’t happen: Betelgeuse powered through the dimming episode and returned to its normal brightness by May of this year. The recovery sparked a new round of speculation, this time about the dimming’s cause. Some scientists attributed the doldrums to a light-blocking dust cloud, for example, whereas others said big star spots on Betelgeuse’s surface were likely to blame. A new study bolsters the dust hypothesis, but adds a twist — Betelgeuse itself apparently coughed up the cloud.