Betelgeuse: The Great Dimming and its Consequences

Andrea Dupree Ph.D. Associate Director, Center for Astrophysics Harvard University

From Sky and Telescope: Betelgeuse is the 10th brightest star in the night sky and marks Orion’s right shoulder (his left shoulder from our point of view). It is a red supergiant, an engorged monster that would stretch out to the orbit of Jupiter if it replaced the Sun in our solar system. Betelgeuse is well on its way to ending its life by detonating as a cataclysmic supernova; meanwhile, astronomers get unprecedented insight into a giant star’s final stages.

The situation became more intriguing in late 2019 when Betelgeuse mysteriously dropped in brightness, an event that came to be known as The Great Dimming. The fading was pronounced enough, more than a magnitude, to notice even with the unaided eye. Lots of possible explanations have been mooted, but now a team led by Andrea Dupree (Center for Astrophysics, Harvard & Smithsonian) thinks they know what happened.

About Andrea Dupree, Ph.D: Andrea Dupree graduated from Wellesley College and received her Ph.D. from Harvard University. Leaving the Harvard College Observatory, she joined the Smithsonian Astrophysical Observatory in 1979 which later formed the Center for Astrophysics. 

Her research focuses on spectroscopy of stars and the interstellar medium, and has ranged across the electromagnetic spectrum from radiofrequencies, infrared, optical, ultraviolet and X-ray regions. She participated in science teams for IUE, EUVE, FUSE, and Kepler. She obtained the first direct image of a star other than the Sun, Betelgeuse, with the Hubble Space Telescope and recently (2020) documented the historic Great Dimming of the supergiant with spatially resolved ultraviolet spectra discovering a gigantic chomospheric outflow event. She is known for studies of young accreting stars, radiofrequency recombination lines, atmospheres of luminous stars, stars in clusters, involving processes of accretion, mass loss, and stellar winds.