Thursday, June 11, 2009

Betelgeuse shrinking, may supernova soon

The star Betelgeuse in Orion, one of the best-known stellar objects in the sky, has shrunk by 15% over the past decade and a half. Bear in mind the size of Betelgeuse: if our own Sun was placed at the center of this star, its outer surface would extend just past the orbit of Jupiter. Or at least it used to not very long ago.

Some astronomers are wondering if Betelgeuse is shrinking because it's used up hydrogen as its main fuel and is now "burning" from helium and other heavier elements. Which would mean that it's in the final stages of a star of its class. When it starts trying to fuse elements like iron and such, some positively hideous astrophysics come into play and Betelgeuse's internal energy is going to overwhelm its immense gravity...

...and we'll get to see a rilly big bang called a supernova.

The supernova of 1054 (the event that created the Crab Nebula) was recorded all over the world, including by Native Americans in what is now the southwestern United States. It was so bright that it could be seen during the daytime and reportedly even cast shadows at night.

If Betelgeuse goes supernova - and some are saying there's a likelihood that it might happen within the lifetimes of many people reading this - then it would very likely dwarf the brilliance of Supernova 1054.

I can't begin to imagine how awesome a sight that would be.

'Course, if Betelgeuse does go supernova, it's probably already happened since the star is around 600 light years away. In which case we're just now finding out about it... but it won't make it any less spectacular "when" it finally happens :-)


Anonymous said...

The problem is that Betelgeuse is close enough that if it goes supernova what we see of it may well be the last things we see.

Radiation from that exploding star might just sterilize the whole planet.

As you say, if it's going to happen it probably already has and there's nothing you and I can do about it.

Disaster this will be!

Ol' You-Know-Who

Anonymous said...

Ol' You-Know-Who,

You may need to do a bit more research, because Betelgeuse's rotational axis is not towards Earth, which means when Betelgeuse does go supernova it will not cause a gamma ray burst in the direction of Earth to even be harmful.

-Drew M.

Anonymous said...

Betelgeuse will cause an acceleration of interstellar gamma rays in all directions. This additional increase could cause global cooling on Earth according to the 2nd Edition of the book CHILLING STARS. Given that the solar sunspot activity is at the minimum it means the protective shield from interstellar gamma rays is at a minimum. Thus additional low level cloud formation will be amplified and these clouds will reflect the energy of the sun back into space - cooling the planet. If severe enough it could trigger another Ice Age.

Get Your Furs Ready

Anonymous said...

"This is but a small example of what sheer raw power can look like.
In January 2008 scientists finally caught a Supernova when it happened, in Earth time. The galaxy is about 18 million light years from Earth so the actual explosion happened long ago. SN 2008D was discovered while an astronomer was looking at this galaxy and checking up on SN 2007uy.

That is a super-blast of x-ray energy that turned out to be about 100 billion times more intense than our Sun. This is the sort of differences that can be expected from a normal star like our Sun to work on your tan and a colossal star going to Supernova and can reduce you to ashes in seconds or total vaporization. Had Earth been 400 light years from an x-ray burst of that magnitude, much or all of the life on this planet would have perished.

Anyone want to be in that neighborhood? Fortunately, this one was 18 million light years away.
Betelgeuse is just about point-blank in galactic terms.

If Betelgeuse blows up as a Supernova, and depending on the nature of that explosion, severity, etc. Earth might be severely damaged in 400 to 600 or so light years after it blows up. Some astrophysicists are saying that when Betelgeuse blows it will be brighter than the full moon in our night sky"

Enough muons to fry us like being in a mircowave.