Betelgeuse fades by more than a magnitude
The nearest red supergiant dimmed visibly enough to change the appearance of Orion to the naked eye, prompting widespread speculation that it was about to explode. Resolved imaging showed the southern hemisphere of the star far darker than usual. Work published in Nature in 2021 attributed the episode to a clump of dust condensing above a patch of the photosphere that had cooled, following an ejection of material from the surface; later analyses indicate that a temperature drop and circumstellar dust extinction contributed in comparable measure. It was mass loss, not imminent collapse.
Observed — measured or witnessed, with the observation cited.
Subjects
- Betelgeuse (Alpha Orionis) · celestial body · Constellation Orion, as seen from Earth · not located
- Red giant and asymptotic giant branch · concept · not located
Evidence
Partly verified — Core facts are sourced; some optional detail is deliberately absent.
A dusty veil shading Betelgeuse during its Great Dimming
Attributes the 2019-2020 Great Dimming to a dust clump condensing above a cooled patch of the photosphere. Journal and volume come from search summaries; the paper was not fetched. Later work, including a 2022 Astrophysical Journal paper describing a surface mass ejection and 2024 tomography, indicates temperature drop and dust extinction contributed in comparable measure.
Nature · 2021 · Partly verified
M. Montarges et al., Nature 594 (2021)
Recorded on Betelgeuse (Alpha Orionis)
- Betelgeuse fades by more than a magnitude
- A close companion to Betelgeuse is probably detected
Related
Related because they share a subject in the Atlas — never because the text looks similar.
- A close companion to Betelgeuse is probably detected · 2025-07 (reported; detection observation December 2024)