Giant Star Boils, Releasing Matter Into Space

Astronomers have long been curious how red supergiants stars, like the bright star, Betelgeuse, manage to shed so much matter into space.

Now, thanks to a collaborative effort which gave scientists a detailed view of the distant star's surface, they have an answer -- it's boiling.

Observations with a trio of 1.8-meter radio telescopes show giant bubble-like structures bobbing on the surface of Betelgeuse, a massive star located 640 light-years away in the constellation Orion.

Emitting about 100,000 times more light than our sun, Betelgeuse is the bright orange star on the shoulder of Orion, also known as The Hunter.

The observations, which are being reported in an upcoming issue of Astronomy & Astrophysics, are the first to spatially resolve the motion of gas on the surface of a star other than the sun, said Keiichi Ohnaka, with the Max-Planck-Institut fur Radioastronomie in Bonn, Germany.

Ohnaka and colleagues found giant gas bubbles -- some as large as the star itself -- moving vigorously up and down in the star's atmosphere.

Betelgeuse is nearing the end of its relatively short life and is expected to explode as a supernova in the next few thousand to hundred thousand years. When it blows, it should be visible from Earth even in daylight.

Scientists aren't sure about the bubbles' origins, but they do point to a likely mechanism for the release of gas and heavy elements into space. These materials become fodder for new stars and planets.

University of California at Berkeley astronomers reported in June that Betelgeuse shrank 15 percent over the past 15 years. At the time, scientists speculated that giant convection cells on the star's surface might be to blame.