Betelgeuse is shrinking! Could it be about to go supernova? Reports from the American Astronomical Society meeting in Pasadena, California this week suggest that over the past 15 years the bright red star has shrunk by 15%. (Press release)
These long-term observations were made by nearly-94-year old Nobel laureate Charles Townes and his colleagues, at UC Berkeley’s Space Sciences Laboratory.
The star is no dimmer than it has been over the time they’ve been looking at it, and the reasons for the shrinkage have so far eluded the team. “We do not know why the star is shrinking,” says team member Edward Wishnow. “Considering all that we know about galaxies and the distant universe, there are still lots of things we don’t know about stars, including what happens as red giants near the ends of their lives.”
So far, so confusing. Few reports offer much explanation. The Register says the shrinking, seen by some including Townes as possible first signs of the star collapsing into a supernova, will be of most concern to fans of Hitchhiker’s Guide to the Galaxy: the red star was home to Zaphod Beeblebrox. “Fans will be hoping that the recent shrinkage of Zaphod’s sun doesn’t mean that, in fact, his homeworld was destroyed hundreds of years before Earth’s abrupt demolition to allow construction of a hyperspace bypass,” says the Register’s Lewis Page.
Over at New Scientist, we can find more in way of clarification. Townes tells them: “Maybe there’s some instability in the star and it’s going to collapse or at least go way down in size or blow off some material, but who knows.” Other astronomers polled for their opinions offer pulsations as a cause of the diminishment, or perhaps that the wonky star was just being looked at from a funny angle. “Often if you look at the simulations, the star is not spherical. It looks like a bad potato,” Graham Harper from the University of Colorado in Boulder told New Scientist.