WR 104: Gamma Ray Bursts and a Musing Lemming

"WR 104 Won't Kill Us After All"
Ian O'Neill, Universe Today (January 7, 2009)

"Early last year, concern was growing for a Wolf-Rayet star named WR 104 that appeared to be aiming right at Earth (see Looking Down the Barrel of A Gamma Ray Burst). A Wolf-Rayet star is a highly unstable star coming to the end of its life, possibly culminating in a powerful, planet-killing gamma-ray burst (GRB). GRBs are collimated beams of high energy gamma-rays, projected from the poles of a collapsing Wolf-Rayet star. It was little wonder that we were concerned when a dying Wolf-Rayet star was found to be pointing right at us! Today, at the AAS in Long Beach, one scientist working at the Keck Telescope has taken a keen interest in WR 104 and shared new findings that show our Solar System may not be bathed in deadly gamma-rays after all...."

As Marvin the Martian said, "Where's the kaboom? There was supposed to be an earth-shattering kaboom!"

Or, in this case, sizzle.

Technical Questions, Technical Answers, and the Lemming

"WR 104: Technical Questions"
Peter Tuthill, School of Physics, Sydney University, NSW 2006, Australia

" This page is for a more in-depth technical discussion of the risk posed by WR 104. There is jargon and techincal [!] stuff ahead, and I won't try to explain all the terms. Ask your local friendly Astronomer if in doubt.

"This discussion focusses [!] on the risk to earth from a potential future gamma ray burst (GRB) in WR 104. Note that this was not a big part of my scientific article published in Astrophysical Journal. The article only had a paragraph or two about this scenario. But for understandable reasons, the press and public have picked up on this aspect of the work. It is maybe a little more widely relevant than, say, 'radiative braking in colliding-wind systems' (which is discussed at length in the paper)...."


In another blog, the Lemming put information about WR 104 into a (fairly) short list:

• WR 104 is
  
  • About 8,000 light years away
    • 'Close' on a cosmic scale
  • A double star
  • 'Pointed' in our direction
    • Maybe
    • Or maybe not
• The stars will explode
  • Probably
  • Within the next 100,000 years
    • Or so
  • Twice
    • It's a double star
• The explosions will produce either
  • Two gamma ray bursts
  • One gamma ray burst
  • No gamma ray bursts
• The gamma ray burst(s), if any, will
  • Get deflected by magnetic fields
  • Be diffused by interstellar gas
  • Cause mass extinctions
    • Like the Ordovician mass extinction
    • Or not

Bottom line: in a hundred thousand years or so, one or both of the stars that humanity calls WR 104 will explode, probably.

One or both may or may not shoot a really intense clump of gamma rays in the general direction of Earth.

These gamma rays may get deflected by the Milky Way galaxy's magnetic fields; or they may get mushed up by the stuff between stars; or they may cause something like the Ordovician extinction event.

That Ordovician thing happened 440,000,000 or so years ago: 'Scientist Declares Doom' headlines notwithstanding, global disasters aren't all that common.

One Thing at a Time

The Lemming is, as this blog's name suggests, "apathetic." Maybe humanity will, a few hundred thousand years from now, face a cataclysmic catastrophe of cosmic scope. Then again, maybe not.

Come to think of it, by then humanity may have spread out a bit by then: which would raise the odds of at least one planetary system that's called "home" being in trouble.

The Lemming is content to let generations yet unborn decide whether to set up shielding, evacuate a few planetary systems, or maybe turn WR 104 so in shoots in another direction.

That last option might have unintended consequences. Someone else might be peeved, if humanity pointed WR 104 toward their home just before it exploded.

Related posts:

• "Oh, Wow! Betelgeuse Has a Couple of Really Hot Spots"
  (January 13, 2010)
• "Betelgeuse is Shrinking: Earth at Grandstand Distance from Supernova?"
  (June 10, 2009)
• "Betelgeuse Blows in 2012? 'Don't Bet on It' "
  (January 22, 2011)
• "Orion: Stars Under Construction and Otherwise"
  (January 9, 2011)
• "Move the Planet - or - Safety First"
  Drifting at the Edge of Time and Space (December 9, 2009)