This makes me wonder about the details of such a sterilizing event. How would it actually work? Say the Earth was in range of a supernova explosion, or in the p

This makes me wonder about the details of such a sterilizing event. How would it actually work? Say the Earth was in range of a supernova explosion, or in the path of a GRB. How would we go out? Would the planet be thrown off its orbit and wander away from the warmth of the Sun, letting us die a slow, freezing death? Would the planet simply be vaporised? Would the atmosphere be incinerated, and anything below it suffocated for lack of oxigen, or maybe burnt by unfiltered solar radiations? Would it leave the planet mostly there, and just destroy anything organic on it? Would it be an instantaneous event? One moment we are there, and one nanosecond after that us and every trace that we ever even existed will be vanished. Or will it take longer? Will we feel it, feel pain, or recognize that it's over, that's it?