(ORDO NEWS) — Analyzing data from NASA’s Hubble Space Telescope and several other observatories, astronomers have concluded that the bright red supergiant star Betelgeuse literally exploded its summit in 2019, losing much of its visible surface and creating a gigantic ejection of surface mass.
The Sun regularly experiences coronal mass ejections, but Betelgeuse has lost 400 billion times more mass due to the ejection than the Sun normally loses.
The star is still slowly recovering from this catastrophic shock.
Red stars lose mass at the end of their lives before exploding in supernovae. However, the behavior of Betelgeuse, oddly enough, is not proof that the star will explode anytime soon. Loss of mass is not necessarily a signal of an impending explosion.
Andrea Dupri of the Harvard-Smithsonian Center for Astrophysics, analyzing the behavior of the star before, after and during the eruption, puts all the pieces of the puzzle together into a coherent story.
“We’ve never seen such a huge ejection of mass from the surface of a star before,” she says. “This is a completely new phenomenon that we can now observe. We see stellar evolution in real time.”
The outburst in 2019 may have been caused by a convective flow more than a million kilometers in diameter escaping from the depths of the star.
It produced impacts and pulsations that tore away part of the photosphere, exposing the colder surface of the star, which was covered in a cloud of dust. Betelgeuse is now trying to recover from this injury.
A fragment of the photosphere, weighing several times more than the Moon, flew into space and cooled down, forming a dust cloud that hides the light of the star from observers from Earth.
Even more fantastically, the supergiant’s 400-day pulsation frequency has disappeared, at least temporarily. For nearly 200 years, astronomers have measured this rhythm from changes in Betelgeuse’s brightness and surface movements. Its violation testifies to the force of the explosion.
The spectra obtained by TRES and Hubble suggest that the outer layers of the star will be able to return to normal.
Betelgeuse is so huge right now that if it were to replace the Sun at the center of our solar system, its outer surface would move beyond the orbit of Jupiter.
Dupree used Hubble to identify hotspots on the surface of Betelgeuse back in 1996. It was the first direct image of a star other than the Sun.
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