As far as stars go, it’s one of the largest, the most luminous, brightest, most massive, and one of the best supernova candidates on the list.  Betelgeuse is huge.  If it were in our sun’s place, it would extend out beyond the orbit of Mars, possibly beyond that of Jupiter.  It is the ninth brightest star in the night sky, and the second brightest (behind Rigel) in the constellation Orion.

The constellation Orion - image courtesy of Zwergelstern, released to PD

The origin of the name “Betelgeuse” is an interesting read in itself, if you happen to be interested in etymology (which I am).  There are also many and varied pronunciations floating around, and “beetle juice” is perfectly acceptable.  I was taught to pronounce it “BET el juz”.  You can avoid the whole issue and just call it “alpha ori/orionis”, if that grabs you.

Betelgeuse is a semi-regular variable star, and is believed to be about 8.5 million years old.  While that makes it an infant compared to our sun (actually, it makes it a fetus), Betelgeuse is old for its type.  Scientists believe it will supernova any time in the next 1,000 years; in fact, it could go tonight.  Betelgeuse has been doing some strange things lately, things which many astronomers believe to be a preamble to supernova.

NASA/JPL/ESA - Hubble - This 1999 image was the first direct image of the surface of a star other than the Sun

When Betelgeuse does supernova, it will become the brightest object in the night sky – easily outshining the Moon.  It would even be perfectly visible during the day.  We would see it increase in brightness over a two-week period, hold intensity for about two or three months, then rapidly dim.  What would be left?  It could be a neutron star remnant, a white dwarf, or even a pulsar.  We don’t have to worry about a gamma ray burst from Betelgeuse; its rotational axis is positioned so that the burst won’t be headed our way.  Not that worrying about it would do any good, you know.  If we were looking down the barrel, Betelgeuse is close enough to fry us to a cinder.

Long an object of speculation and study, Betelgeuse has been receiving even more attention with the advent of the new “super telescopes” like Gemini.  It’s fair to say that at any moment, someone… somewhere… is looking at Betelgeuse.

Betelgeuse, image by ESO's Very Large Telescope

Many people think it would be really cool to watch Betelgeuse supernova.  Maybe.  If I sound grouchy here it’s because although I would like to see a supernova that close (and we should be perfectly safe at this distance), I don’t want to lose Betelgeuse.  Sure, we wouldn’t really lose Betelgeuse… SOMETHING will still be there… but it won’t be that big, beautiful red star I’m used to seeing.

Keep looking up, Alejandro.