Betelgeuse, best known for its role in the constellation Orion and being played by Michael Keaton, is dying. And unlike other dying stars, it seems to be shrinking, too.
Betelgeuse is so large and bright (and so relatively close) that it's had its surface photographed and its size measured, and it appears larger than most other stars when viewed by the Hubble Telescope. But it's getting older and, like its red giant counterparts, dying. But unlike other red giants, which scientists have observed swelling before death, Betelgeuse is shrinking.
In 1993, measurements put Betelgeuse's radius at about 5.5 astronomical units (AU), where one AU equals the average Earth-sun distance of 93 million miles, or about 150 million km. Since then it has shrunk in size by 15 percent. That means the star's radius has contracted by a distance equal to the orbit of Venus.
"To see this change is very striking," said Charles Townes, a UC Berkeley professor emeritus of physics. "We will be watching it carefully over the next few years to see if it will keep contracting or will go back up in size."
Scientists don't know if this is normal behavior, a potential harbinger of its imminent demise or part of an inevitable decline. For the moment, though, Betelgeuse continues to shine as bright as ever.
Popular Giant Star Shrinks Mysteriously [Live Science]