You DO know how black holes are made don't you? Extra-large supernovas result in black holes. You want to waste another GTVA star system?
In any case the SubSpace Rift could lead to:
If the Mass and size of the Sun is not enough big to create a Dark Hole, but enough to go into SuperNova (and not a Nova), then a Neutron Star will result, in any case, the gravity field and Mass of a Neutron Star is truly impressive, I believe the damage done to the system would just be very much like the same.
In the other case, if the size and mass is not enough to go into SuperNova, the Sun will start rising it's temperature and just glowing more intense until, we would all get a nice tan over the skin (no, it's a joke, we'll burn to death for sure, and so anything in that system probabily).
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Of course we don't know how a SubSpace Rift would affect a Ship, that's my whole point for think why the hell the Sathanas blow the Sun an just not the ships with it, without loose any Sathanas...this make me thinks it just doesn't work against ships with Warp Drives...
In series the SubSpace Rift is supposed to create a Warp Hole, the same you use to Warp, but in this case it does damages. However if the Ship has no Warp Drive and stands before the SubSpace Rift for some time it's Hull starts to being rip. A ship would be able to Warp just through it with a Warp Drive without suffering damage.
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Another question is why in the FMV the SubSpace Rift was Green and not blue, if you remember SubSpace horizon colour is blue, and so the Warp is also Blue.
Aside from SubSpace and Normal Space, there are supposed to be other unexplored Space Layers, that didn't really appear in the FS universe:
Maybe the Green colour was just to reflect it was a Rift, but do it was a SubSpace one ?. A rift should be able to happen with any kind of space.
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I recommend that you read this, you won't learn it in FreeSpace, at least for the ones that are interested in how Space Layers work:
http://personal.davidtulga.com/sct.htmOf course most of the content is fictional, but before say something remember the past:
revolutionary: "I say the Earth is round"
Ignorant people: "He is crazy, let's kill him/her"