Data from paper Dupree et al. 2022, Apj

The bright supergiant, Betelgeuse (Alpha Orionis, HD 39801), underwent
a historic optical dimming during 2020 January 27 $-$ February 13. Many imaging and spectroscopic observations across the
electromagnetic spectrum were obtained
prior to, during, and subsequent to this dimming event.
These observations of Betelgeuse
reveal that a substantial surface
mass ejection (SME) occurred and moved out through the
extended atmosphere of the supergiant. A photospheric shock occurred in 2019 January - March, progressed through the
extended atmosphere of the star during the following 11 months and led to dust production in the atmosphere. Resulting from the
substantial mass outflow, the stellar photosphere
was left with lower temperatures and the chromosphere with a lower density. The mass ejected could represent a
significant fraction of the total annual mass loss rate from the star suggesting that episodic mass loss events
can contribute an amount comparable to that of the stellar wind.
Following the SME, Betelgeuse was left with a cooler average photosphere, an unusual short photometric oscillation, reduced
velocity excursions, and the disappearance of the $\sim$400-day pulsation in
the optical and radial velocity for more than
two years following the Great Dimming.
This DOI contains the ultraviolet spectra obtained at various positions on the stellar disk over 4 years 2019-2022.