New Images Of Betelgeuse Reveal Mysterious Hot Spots
New images taken by the e-MERLIN radio telescope operated from the Jodrell Bank Observatory in Cheshire, England, reveal massive regions of unexpectedly hot gas in the star Betelgeuse’s outer atmosphere along with a cooler arc of gas that alone weighs as much as the Earth.
Roughly 1,000 times larger than our Sun, Betelgeuse is located 650 light years from Earth and can easily be identified by the unaided eye as the red star on the shoulder of Orion the Hunter.
The images, published in the journal Monthly Notices of the Royal Astronomical Society, reveal an atmosphere extending five times beyond the visual surface of the star with two hot spots measuring approximately 4,000 to 5,000 Kelvin, or an estimated 3,000 Kelvin higher than the average temperature of its radio surface.
The arc of cool air, on the other hand, is estimated at 150 Kelvin and lies as far away from the star as Pluto is from the Sun.
While lead author Anita Richards, from the University of Manchester, said it’s not clear why the hot spots are so hot, she explained in a press release that one possibility is that shock waves caused either by the star’s pulsations or convection in its outer layer are compressing and thus heating the gas.
Another possibility, she said, is that the outer atmosphere is simply “patchy” and that, as a result, the spots are really just holes, or windows, to further below.
The cool air, she said, is thought to be caused by a period of increased mass loss from the star though its “relationship to structures like the hot spots, which lie much closer in, within the star’s outer atmosphere, is unknown.”
In all, Richards said Betelgeuse produces a wind equivalent to losing the mass of the Earth every three years. The stellar winds, enriched with chemicals, will go on into the next generation of star and planet formation.
However, despite being such a crucial part of the life cycle of matter, scientists are still not sure what the mechanism behind the mass loss is.
For this reason, Richards said she and her team will continue radio and microwave observations to help determine what is driving the stellar wind and producing the hot spots.
Doing so won’t “just tell us how the elements that form the building blocks of life are being returned to space,” Anita said, but also “help determine how long it is before Betelgeuse explodes as a supernova.”