The giant star Betelgeuse caused astonishment with a spectacular drop in brightness that began at the end of 2019 and lasted until February 2020. Images from the Hubble telescope now provide a new attempt to explain the mysterious darkening, reports CNet.
Astronomers at the Harvard Smithsonian Center for Astrophysics studied the ultraviolet light emitted by the star during the eclipse. By looking at the star at UV wavelengths, they could see the surface and atmosphere better. They discovered how a mass of bright, hot material moved outward from the southern hemisphere of the celestial body at a speed of almost 322,000 kilometers per hour and was finally ejected into space, as they noted in a study published Thursday in The Astrophysical Journal.
Harvard researcher Andrea Dupree claims that this material was two to four times brighter than the normal brightness of the star quoted in a Harvard communication. About a month after the eruption, the southern part of the star has darkened noticeably.
Dust cloud
The astronomer assumes that the material cooled on its way through space and formed a dense cloud of dust that partially obscured Betelgeuse. The earth was in a perfect position to see the dust cloud front, said Dupree.
Astronomers can only speculate about the cause of the eruption. They assume that it is related to the star’s pulsation cycle.
With their study, the astronomers contradict a theory published in June that the darkening with star spots explained. But was over a cloud of dust also already speculated.
Further blackout
But the star continues to behave strangely. Observations by NASA’s Stereo Space Telescope (Solar and Terrestrial Relations Observatory) between late June and early August showedthat the star was unexpectedly darker again.
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