Betelgeuse did not explode as a supernova, as some expected. The star was hidden by a cloud of dust. But its behavior does not cease to intrigue: the interior of the star seems to “bounce”.
The loss of brightness of the star Betelgeuse, observed between the end of 2019 and the beginning of 2020, continues to fascinate. Its impressive drop in luminosity could have made it seem that Betelgeuse was ready to explode, which could cause a supernova. In reality, the star is not dead: Betelgeuse has temporarily been concealed by a cloud of dust.
New observations of the star, made with the Hubble Space Telescope, show that Betelgeuse is “recovering” after this event. In a press release published on April 11, 2022, accompanying a study submitted to The Astrophysical JournalNASA reports that the star continues to behave strangely, however.
Betelgeuse experienced an upheaval
” Betelgeuse suffered a mass ejection at the surface. The aftermath of the dimming event clearly affected the star’s atmosphere “, we read in this study. This type of event is reminiscent of coronal mass ejections that occur on the Sun. These ejections sometimes accompany solar flares: they are magnetized clouds, propagating in the interplanetary medium. The ejection from Betelgeuse is even more impressive than those from the Sun: it expelled 400 billion times more mass than a “classic” coronal mass ejection.
It takes time for Betelgeuse to recover from this ejection, which NASA describes as an “upheaval”. ” Betelgeuse is still doing some very unusual things right now: the interior is sort of bouncing “Describes Andrea Dupree, co-author of the study, astrophysicist at the Harvard-Smithsonian Center for Astrophysics, quoted by NASA.
Inside the star, “an unbalanced washing machine tub”
For 200 years, researchers who have been interested in the star have been able to observe its variability, with oscillations over a period of 400 days. However, these pulsations seem today disturbed, because the scientists noted that they had disappeared. The cells inside the star, responsible for this pulsation in normal times, could be ” swaying like an unbalanced washing machine tub “, describes NASA. Another rather telling image, used by the space agency, is that of a gelatin dessert, placed on a plate that we would be shaking.
Thanks to all this data gathered on the evolution of Betelgeuse, before, during and after the ejection, scientists can retrace the history of this rarely observed event. ” We observe stellar evolution in real time sums up Andrea Dupree.