PHYS 1000 Lecture Notes - Lecture 9: Standard Solar Model, Corona, Solar Wind
Document Summary
Outer layers are not to scale (photo in slide). The core is where nuclear fusion takes place. The sun has a sharp edge because most of the radiation comes from the very thin photosphe(cid:396)e (cid:894)(cid:862)su(cid:396)fa(cid:272)e(cid:863)(cid:895). Luminosity total energy radiated by the sun can be calculated from the fraction of that energy that (cid:396)ea(cid:272)hes ea(cid:396)th. The sola(cid:396) (cid:272)o(cid:374)sta(cid:374)t is ho(cid:449) (cid:373)u(cid:272)h e(cid:374)e(cid:396)gy (cid:396)ea(cid:272)hes 1 s(cid:395)ua(cid:396)e (cid:373)ete(cid:396) at the top of the ea(cid:396)th"s atmosphere per second. Total luminosity is about 4 x 1026 w the equivalent of about 100 billion 1- megaton nuclear bombs per second. The u(cid:374)"s lu(cid:373)i(cid:374)osity, te(cid:373)pe(cid:396)atu(cid:396)e a(cid:374)d (cid:396)adius do (cid:374)ot (cid:448)a(cid:396)y (cid:373)u(cid:272)h from day to day. The sun does not spin as one solid body. The rotation period at the equator is about 25 days. The polar rotation period is not known with certainty, but it may be as long as 36 days. Mathematical models, consistent with observation and physical principles, provide information about the u(cid:374)"s i(cid:374)te(cid:396)io(cid:396).