NASA | GSFC | STScI | HubbleSite | 2020 Aug 13
Observations by NASA's Hubble Space Telescope are showing that the unexpected dimming of the supergiant star Betelgeuse was most likely caused by an immense amount of hot material ejected into space, forming a dust cloud that blocked starlight coming from Betelgeuse's surface.
- This four-panel graphic illustrates how the southern region of the rapidly evolving, bright, red supergiant star Betelgeuse may have suddenly become fainter for several months during late 2019 and early 2020. In the first two panels, as seen in ultraviolet light with the Hubble Space Telescope, a bright, hot blob of plasma is ejected from the emergence of a huge convection cell on the star's surface. In panel three, the outflowing, expelled gas rapidly expands outward. It cools to form an enormous cloud of obscuring dust grains. The final panel reveals the huge dust cloud blocking the light (as seen from Earth) from a quarter of the star's surface. Illustration Credit: NASA, ESA, and E. Wheatley (STScI)
Hubble researchers suggest that the dust cloud formed when superhot plasma unleashed from an upwelling of a large convection cell on the star's surface passed through the hot atmosphere to the colder outer layers, where it cooled and formed dust grains. The resulting dust cloud blocked light from about a quarter of the star's surface, beginning in late 2019. By April 2020, the star returned to normal brightness.
Betelgeuse is an aging, red supergiant star that has swelled in size due to complex, evolving changes in its nuclear fusion furnace at the core. The star is so huge now that if it replaced the Sun at the center of our solar system, its outer surface would extend past the orbit of Jupiter.
The unprecedented phenomenon for Betelgeuse's great dimming, eventually noticeable to even the naked eye, started in October 2019. By mid-February 2020, the monster star had lost more than two-thirds of its brilliance. ...
Several months of Hubble's ultraviolet-light spectroscopic observations of Betelgeuse, beginning in January 2019, yield a timeline leading up to the darkening. These observations provide important new clues to the mechanism behind the dimming.
Hubble captured signs of dense, heated material moving through the star's atmosphere in September, October, and November 2019. Then, in December, several ground-based telescopes observed the star decreasing in brightness in its southern hemisphere. ...
Hubble Helps Uncover the Mystery of the Dimming of Betelgeuse
ESA Hubble Science Release | 2020 Aug 13
Mysterious Dimming of Betelgeuse: Dust Clearing Up
Leibniz Institute for Astrophysics, Potsdam | 2020 Aug 13
Scientists Suggest Stellar "Sneeze" as Reason for Betelgeuse's Massive Dimming
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STEREO's Lone View of Betelgeuse Reveals More Strange Behavior
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Spatially Resolved Ultraviolet Spectroscopy of the Great Dimming of Betelgeuse ~ Andrea K. Dupree et al
- Astrophysical Journal 899(1):68 (2020 Aug 10) DOI: 10.3847/1538-4357/aba516
- arXiv.org > astro-ph > arXiv:2008.04945 > 11 Aug 2020
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