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Good morning, I know some similar questions have been asked but I don't find a convincing answer in these. Excuse me if I have missed the answer.
My question is:
I have learned that some black holes are formed by contraction of stard ( the exact processus does not matter here ). The problem is that the time dilatation due to gravitation is increasing with the contraction being infinite when all the matter pass inside the horizon.
But for an external observer it will take an infinite amount of time so that the black holes we see today are nearly perfect black holes but not totally since all the matter have not passed the horizon. Am I wrong here?
Furthermore, these black holes could not be totally black since all the matter of the original stars do not pass the horizon. So it would be possible for them to emit a bit of light no?
But this is not what I read so if someone could explain me, I would be grateful to him ;)