Is Betelgeuse About to Go Supernova?

Is Betelgeuse, a red giant star about six hundred light years from our solar system, about to explode? Some scientists believe that Betelgeuse is exhibiting the signs of a star about to go supernova.

According to a report in Fox News, "The red giant Betelgeuse, once so large it would reach out to Jupiter's orbit if placed in our own solar system, has shrunk by 15 percent over the past decade in a half, although it's just as bright as it's ever been."

Red giant stars such as Betelgeuse, "--are thought to have short, complicated and violent lifespans. Lasting at most a few million years, they quickly burn out their hydrogen fuel and then switch to helium, carbon and other elements in a series of partial collapses, refuelings and restarts...Eventually, the huge star may become a nesting doll of elements, with a mixed iron-nickel core surrounded by onion-like layers of silicon, oxygen, neon, carbon, helium and hydrogen. As the iron fuel runs out, it may explode into a supernova, blasting newly created elements out into the universe and leaving behind a small, incredibly dense neutron star."

If and when Betelgeuse explodes, it will be the nearest observed supernova in centuries. The last supernova observed in our galaxy was Cassiopeia A in 1680. Before that, the astronomer Kepler observed a supernova in 1604 and Tycho one in 1572. A supernova occurred in the Large Magellanic Cloud, a companion galaxy to our own, in 1987.

The earliest recorded supernova was observed by Chinese astronomers in the year 185. A supernova that occurred in 1054 created the Crab Nebula.

There is, of course, no way of knowing when or if Betelgeuse might become a supernova. It might occur thousands of years from now, an eye blink in interstellar time, a very long time in the lives in human beings.

But should Betelgeuse explode, astronomers will have a chance to observe in real time with instruments unknown to Tycho, Kepler, or the ancient Chinese, the phenomenon of a supernova relatively close to the Earth. Most of Betelgeuse will be blasted into interstellar space, eventually creating a gorgeous nebula. If the core is less than twenty solar masses, it will become a neutron star, perhaps observed as a pulsar or x-ray binary. Larger than twenty solar masses, the core will collapse in on itself and eventually become a black hole, from which nothing can escape.

When and if Betelgeuse explodes, it will be a spectacular sight in the night sky over Earth.

The prospect of Betegeuse exploding has caused some consternation among people obssessed with the end of the world. The next date for the end of the world, according to a Mayan calender, is in December, 2012. While it is true that if a supernova explodes close enough to the Earth, the resulting radiation and charged particles could very well cause great havok to the Earth's biosphere. But Betelgeuse, being six hundred light years away from the Earth, seems to be far beyond the danger zone for such a catastrophe to occur.

Betelgeuse also figures prominently in fiction. The home of couple of characters in A Hitchhiker's Guide to the Galaxy is said to be near Betelgeause. The novel version of Planet of the Apes places said planet in orbit around Betelgeuse. In film, Beetlejuice is almost certainly a corruption of Betelgeuse. Betelgeuse is also mentioned in Star Trek: The Motion Picture.

Sources: Nearby Star May Be Getting Ready to Explode, Fox News, June 11th, 2009

Supernovae, NASA Goddard