In line with end-of-the-world prophecies linked to Maya calendars, there’s sudden noise on the Internet that Betelgeuse (the bright red star that marks Orion’s left shoulder) will become a supernova in 2012. The segue is that this will first give us Tattooine-like sunsets, then singe earth and all upon it.
Betelgeuse is a gas-shrouded red supergiant of about 20 solar masses whose circumference would extend to Jupiter and whose hydrogen fuel has run out. This does mean that its days are numbered and its end will be spectacular: when it explodes, it will be visible in broad daylight and will cast shadows as strong as those of the full moon. However, it’s easy to find out that Betelgeuse is about 600 light years away. So it’s not close enough to harm us (the radius for harm is 25 ly or less). Furthermore, if the explosion becomes visible to us in 2012, the event actually happened sometime around 1400 CE. A more in-depth search also reveals that the star’s axis does not point in the direction of Earth, precluding a potentially lethal directed gamma ray burst.
Betelgeuse is a runaway: it started life as a hot blue star in the prolific stellar nursery around Orion’s belt. This region, which includes the famous nebula that forms the middle “star” of Orion’s sword, is still giving birth to new stars. So after Betelgeuse has dwindled to a neutron cinder, it may have a successor. But its death will change the shape of perhaps the best-known constellation – a reminder that in our universe everything is born and will die.
Adrienne Rich wrote her elegiac poem Orion before many details about Betelgeuse became known. Yet she knew more and said it far better than the apocalypse pornographers of the Internets:
Far back when I went zig-zagging
through tamarack pastures
you were my genius, you
my cast-iron Viking, my helmed
lion-heart king in prison.
Years later now you’re young
my fierce half-brother, staring
down from that simplified west
your breast open, your belt dragged down
by an oldfashioned thing, a sword
the last bravado you won’t give over
though it weighs you down as you stride
and the stars in it are dim
and maybe have stopped burning.
But you burn, and I know it;
as I throw back my head to take you in
an old transfusion happens again:
divine astronomy is nothing to it.
Pity is not your forte.
Calmly you ache up there
pinned aloft in your crow’s nest,
my speechless pirate!
You take it all for granted
and when I look you back
it’s with a starlike eye
shooting its cold and egotistical spear
where it can do least damage.
Breathe deep! No hurt, no pardon
out here in the cold with you
you with your back to the wall.
Images: Top, data-congruent rendering of Betelgeuse (ESO, L. Calçada); Bottom, Orion (Hubble ESA, Akira Fujii)