Stars go supernova occasionally
Not spontaneously, with only a handful of years’ notice, they don’t.
I’m all for Trek science being a little weird, but it seems very likely that there was some funny business going on for the star to suddenly blow up and threaten the entire galaxy.
Yeah, with Star Trek-level technology, you should be able to tell to the week when a star will nova about 10,000 years in advance.
The wiggle room within Star Trek is that the Tkon Empire was supposedly wiped out by a supernova despite being a highly advanced civilization, and in “Second Sight” the DS9 crew boosts the top speed of a ship to warp 9.5, which suggests that a supernova can have superliminal consequences.
But there’s nothing to suggest the Tkon supernova was a natural phenomenon, and the hijinks they were up to in “Second Sight” certainly wasn’t.