Galaxy core explosion?

[cosmicalstorm]

I've read a couple of scifi stories where the concept of a galaxy core explosion is mentioned.

I'm just wondering if this would be possible in reality?
Lets say in a really densely packed part of a galactic core, could one supernova trigger other stars to go supernova and thus create an expanding bubble of additional supernovas?

(I've tried to google the subject but I mainly found discussions about quasars, GRB's and hypernovas. I also tried searching the forum but terms such as explosion and galaxy occur fairly frequently on this board.)

[Solauren]

Impossible.

Supernova are caused by stars running out of nuclear fuel, or by a Dwarf start stipping alot of matter from a larger companion star.

In order for you to have a sustained, multiple-event supernova, you'd have to have alot of very large starts very close together. To close to have occured naturally (according to modern star building theory anyway) without merging into each other and eventually collapsing into a black hole.

[Simon_Jester]

I'm guessing the stories cosmicalstorm read were by Larry Niven; the galactic core explosion with its predictable (extremely long range) consequences for the stars out near Earth are a major plot point in his Known Space setting. Could be anyone, though, I guess.

In any event, I'm not qualified to discuss whether or not a supernova chain reaction is possible. As best as I can determine from relatively limited research, what used to be interpreted as "exploding" galaxies are what are now called "starburst" galaxies. In such galaxies, the rate of star formation is accelerated, creating lots of big, short-lived stars that predictably go supernova a while later. If you're looking at a starburst galaxy several million years after the stellar formation process goes into overdrive, it looks like a galaxy where there are "too many" supernovae, because there are a lot more blue giant stars ready to go supernova than there would be in a normal galaxy that wasn't making stars as fast.

For the astronomers: did I get that right?

[ThomasP]

There was also mention of a galactic core-burst in Greg Egan's Diaspora as well.

It didn't sound anything like a chain reaction of supernovae, so much as the core itself undergoing some kind of massive explosion event.

I confess I couldn't find any primary source discussing the idea, either, even though Egan tends to be fairly meticulous in his fiction.

[Wyrm]

Even in the star-dense region of the galactic core, supernovae are too far apart for the kind of chain-reaction that Niven envisions. Type II supernovae occur when the iron core in the center reaches a critical mass and collapses. Although an incoming shockwave can cause a starquake, any distortion that could change the dynamics enough to make a significant difference on when the star would explode would also disrupt the star.

A type I supernova would be delayed if affected at all, as the shockwave would most likely temporarily interrupt the inflow of gas onto the white dwarf.

That said, there does seem to be a starburst coming in the near future (200 million years), but this has more to do with the fact that a bunch of supernova candidate stars will be formed in a very short time — and will therefore explode in a very short time — rather than a chain reaction.

[Starglider]

There was also mention of a galactic core-burst in Greg Egan's Diaspora as well.

It didn't sound anything like a chain reaction of supernovae, so much as the core itself undergoing some kind of massive explosion event.

That event was based on fantasy physics; it involved a very fast collapse of the accretion disc around the central supermassive black hole due to the 'bleeding' of angular momentum into higher-dimensional spin. There is (as far as we know) no equivalent in real physics.