Hi, I've just registered in the forum because I have a couple of Physics questions. I'm not a specialist, and furthermore English is not my mother tongue, so please be indulgent with me. As far as i know (please correct if not), only two sources of natural 'extraterrestrial' neutrinos have been detected by now, the Sun and the supernova SN1987A. But (as far as I know too) they also are the only known particles that are not significantly attenuated by their travel through the interstellar medium (and that's one of the reasons because they're so interesting...) So my question is, shouldn't we be detecting neutrinos from a great amount of extrasolar sources? Why not, please? Thank you very much in advance, and please relocate this question if it isn't in the appropiate section.