Honestly, I'd have to say "How long after sunset can you pick out
Polaris with the unaided eye?

Honestly, I'd have to answer, "Until shortly before sunrise."

How 'bout, "How soon after sunset can you pick out Polaris
with the unaided eye?"
sorry, just playin' along...

btw, did you hear about the man who stayed up all night
waiting to see where the sun went after it sets?

....it finally dawned on him.