Betelgeuse, a red giant on the brink of death, continues to show unusual behavior. After the Great Blackout, which occurred in late 2019 and early 2020, the star became unusually bright. It is now the seventh brightest star in the sky, while it normally ranks tenth. This has led to speculation that Betelgeuse is preparing to explode in a spectacularly large supernova.
However, scientists believe it’s too early to tell, and it’s likely that this behavior is due to ongoing fluctuations after the Great Blackout of 2019, and the star will return to normal within a decade.
Betelgeuse is one of the most interesting stars in the sky. It is about 700 light-years from Earth and is a red giant in the last stage of its life. It is also an unusual star for a red giant because it was previously a monster blue-white O-type star, the most massive class of stars.
Betelgeuse has changed its spectral type because it has almost exhausted its hydrogen reserves. It now burns helium into carbon and oxygen and has expanded to a gigantic size: about 764 times the size of the Sun and about 16.5 to 19 times its mass.
Eventually it will run out of fuel to burn, become a supernova, eject its outer material, and its core will collapse into a neutron star.
Before the Great Blackout, Betelgeuse also had periodic fluctuations in brightness. The longest of these cycles is about 5.9 years and the other is 400 days. But it seems that the Great Blackout caused changes in these oscillations.
A new paper by astrophysicist Morgan McLeod of the Harvard-Smithsonian Center for Astrophysics has shown that the 400-day cycle appears to have been halved. This pulsational cycle is probably caused by expansion and contraction within the star. According to simulations carried out by MacLeod and his colleagues, the convective flow inside Betelgeuse may have risen and become material that separates from the star.
