Each star has one common effect that fires most of the time (or has a chance of firing most of the time), and one that's much less common but more powerful.
Just to clarify and see if I got it right. Each of the stars has two possible outcomes, one which is more common and one which is less (is it safe to assume that the chance of the less common is the same for all stars?).
On top of that, some, but not all, of those outcomes have bonus events.
For example a red dwarf has two outcomes and no bonuses.
A blue giant has two outcomes, and one of those outcomes has a possibility of a bonus stun.
A magnetar has a different bonus effect for each of the outcomes.