AST 101 Lecture Notes - Lecture 16: White Dwarf, Red Giant, Black-Body Radiation
Document Summary
Hot innards emit blackbody radiation because of its temperature. Cooler gases (cid:449)ithi(cid:374) the su(cid:374)"s at(cid:373)osphere a(cid:271)sor(cid:271) the (cid:449)a(cid:448)ele(cid:374)gths (cid:272)orrespo(cid:374)di(cid:374)g to their energy-level transitions, giving rise to the dark lines in the spectrum. Nuclear fusion a nuclear reaction involving building larger nuclei out of smaller ones. Electrons within the sun are so hot and are under so much pressure that they are torn off of their atoms. Like charges repel each other: temperature of sun can overpower that. Create an attractive nuclear force that will hold them together. One changes to a neutron, creating a new atomic nucleus between the two of them. P + p + e = np. Npp + npp = nnpp + p + p (nnpp is helium) Is the (cid:272)urre(cid:374)t sour(cid:272)e of the su(cid:374)"s e(cid:374)ergy a(cid:374)d (cid:373)ost stars i(cid:374) the u(cid:374)i(cid:448)erse: releases millions of electron volts per atom, hydrogen to helium fusion. Heliu(cid:373) (cid:449)ill e(cid:448)e(cid:374)tually (cid:271)uild up i(cid:374) the su(cid:374)"s (cid:272)ore.