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by hardlianotion 2766 days ago
If it is pointed directly at us, 8000 light years away is close enough to make the gamma ray burst a possible extinction event.

https://www.syfy.com/syfywire/wr-104-nearby-gamma-ray-burst

2 comments

I enjoyed Phil's article on it, thanks for the link. The take away is pretty good, a lot of things would have to align for it to hit us, and if it did, the effects range from 'none' to 'extinction'. Which is true for a lot of things (like asteroids)

It suggests another interesting plot for a science fiction novel, an alien attack force is coming to invade the planet, and a GRB event goes of across the galaxy, missing Earth completely but killing everything on the alien armada. Which slowly drifts toward the inner solar system.

An extinction-level GRB was an important plot device in Greg Egan's excellent novel, Diaspora
>If it is pointed directly at us

Is a gamma burst directional, or spherical in term of high-energy emission?

You can read the Wikipedia article here: https://en.wikipedia.org/wiki/Gamma-ray_burst but to summarize the burst is believed to be a 'jet' this forms as part of the explosion of the spinning masses.
Directional, and this one is apparently pointed about 30 degrees away from us.
Can you point me to a source for that "about 30 degrees away from us"? I haven't seen it.

And, how directional? All the energy is spread across half the sky? Only 10 degrees? Or only one degree? Is 30 degrees enough for it to completely miss us? Mostly miss us? Or are we still in the danger cone?

Finally, in a binary star system, is that 30 degrees going to change as the stars orbit each other? (Worse, IIRC, there's a third, more distant star. Can it change the orbit of the other two in a way that shifts that 30 degrees?)

It’s mentioned in this article: https://www.syfy.com/syfywire/is-this-cosmic-sprinkler-surro... .

My impression is that a GRB beam is on the order of a few degrees, but I can’t find that reference now.