Meet Orion:
Possibly the most recognizable constellation in the sky, Orion contains one of the largest stars in the known universe: Betelguese. (pronounced like Beetlejuice, or Beetlejuize) Thats it on Orion's right shoulder, the yellowish-orange one. Its the 9th brightest star in the night sky.
Why is it so bright? Betelguese is a red supergiant. Its huge. If you put it smack dab in the middle of our solar system, it would extend out to Saturn's orbit. Supergiants tend to run hotter due to increased mass and gravitational pressure and therefore, despite being comprised of much much much more fuel (hydrogen) than smaller stars, they tend to have a much shorter lifespan because they burn through their supply of fuel quicker. So, while Betelguese is relatively young in star-years (about 8.5 million years old) it is actually VERY old compared to most other supergiants which tend to burn through their supply of hydrogen in roughly 1 million years. When a star has exhausted its supply of hydrogen, it moves on to heavier elements such as helium, until it begins to finally accumulate iron in its core, and nuclear fusion stops. As soon as nuclear fusion stops, the star goes through a state of gravitational collapse and the star explodes, shedding off its outer layers in a gigantic glowing blob in the sky. In other words, the star goes "supernova".
Why now?Scientists have noted that, since 1993, Betelguese has shrunk about 15%, and is increasing its shrink rate. In fact, current observations from the Mauna Kea observatory suggest that Betelguese is collapsing at such a rate (around 450-470mph), that the star is no longer round, but is in fact oval-shaped (think smushed). This is due to the fact that since stars rotate (and rotate faster at the equator than at the poles due to angular momentum) the collapse is happening faster at the polar axis than at the equatorial axis, creating the oval shape.
What does this mean? Well it means that although scientists have always pointed to Betelguese as a candidate for supernova in our observable universe, it was always considered to be happening in roughly the next 1,000 years or so. This new evidence suggests that it may be much sooner than that, possibly within months or years.
What will it look like? Well the last supernova observable by the naked eye was in the year 1054. The Crab Supernova, as it is called, was visible during daylight hours for 23 days, and observable in the night sky for 653 days. And THAT supernova was about 6000 light years away. THIS one would be about 600. Think twice as bright as a full moon, so areas where Betelguese is visible at night would have 24 hours of light for at least a few weeks, and this is something we'd be able to see at night for a few years.
"So what?" you may say. Well, being as this only happens once in a millennium, it would certainly be something to be able to say you were there for. And, god forbid it happens in 2012.....we may just see the crazies come out of the woodwork and claim it as more proof that the world is ending!
