Death From Space — Gamma-Ray Bursts Explained

There are cosmic snipers firing at random into the universe. What are they and what happens if they hit us?

I am an Astrophysics major (although this knowledge isn’t from a class), we don’t currently know of any stars large enough to create a GRB that are pointed at us and close enough to cause mass extinction level damage. The closest possibility is WR 104, a Wolf Rayet star (basically a star that’s so big and powerful that it’s blasting off a sizeable fraction of its mass in its solar wind, although there are other traits), which is pointed vaguely towards us and very large, but it’s not certain that it will create a GRB (one originating in a high metallicity star would be unusual) and only certain attempts to measure its axis have shown it as anywhere near pointed at us, other methods have found it pointed well to the side and therefore not a threat.

Short duration GRB, which are created by colliding neutron stars, would be harder to identify as those are small enough that us failing to detect them is a real possibility at the ranges close enough to be a threat, but those are even more rare, and release less energy than long duration ones.