Betelgeuse is a giant red star that scientists expect to go supernova any time soon. However, a new study shows that this might not be the case. It takes Betelgeuse another 100,000 years until it goes supernova.
The star was suspected by some to be on the brink of a supernova event when it lost two drops in its brightness in a matter of months. NASA, using its super-powerful Hubble Space Telescope, speculated that the dimming event was caused by a large dust cloud. Likely caused when the star expulsed an enormous amount of mass. “This material was two to four times more luminous than the star’s normal brightness. And then, about a month later, the south part of Betelgeuse dimmed conspicuously as the star grew fainter. We think it is possible that a dark cloud resulted from the outflow that Hubble detected. Only Hubble gives us this evidence that led up to the dimming.” Said dr. Andrea Dupree.
Now, the chances of Beutelgeus going supernova any time soon seem to have become even slimmer. A study by the Australian National University, led by Dr. Meridith Joyce found that the star’s lifespan has likely been underestimated. The star is also smaller and much closer to earth than previous estimates put it.
Co-author Dr. László Molnár gave further insights about the actual size of the red giant. “The actual physical size of Betelgeuse has been a bit of a mystery – earlier studies suggested it could be bigger than the orbit of Jupiter. Our results say Betelgeuse only extends out to two-thirds of that, with a radius 750 times the radius of the sun,” Dr. Molnár stated.
“Once we had the physical size of the star, we were able to determine the distance from Earth. Our results show it’s a mere 530 light-years from us – 25 percent closer than previously thought.”
Betelgeuse is still scientists’ best chance of being able to study a supernova in the ´near´ future. “It’s still a really big deal when a supernova goes off. And this is our closest candidate. It gives us a rare opportunity to study what happens to stars like this before they explode,” Dr. Joyce said.
Image credit: ALMA (ESO/NAOJ/NRAO)/E. O’Gorman/P. Kervella
Journal: M., Joyce, et. al., Standing on the Shoulders of Giants: New Mass and Distance Estimates for Betelgeuse through Combined Evolutionary, Asteroseismic, and Hydrodynamic Simulations with MESA, The Astrophysical Journal, volume 902, 2020.