ASTR 101 Chapter Notes - Chapter 15-19: Photosphere, Inverse-Square Law, Nuclear Power
Document Summary
15. 1 the structure and composition of the sun. Similarity between sun and other stars shown by cecilia payne-gaposchkin (1925) The sun is hot enough that most atoms are ionized (hot ionized gas is plasma) In the 19th century, we observed a spectral line at 530. 3 nm. We figured out that this was due to highly ionized iron (lost 13 electrons) Sun"s atmosphere is more than a million degrees. The layers of the sun beneath the visible surface. It is about 20% of the sun"s size with temperature of 15 million k. The radiative zone starts at 25% of the distance to the solar surface and extends to about 70% Light generated in the core is slowly transported through the radiative zone due to the high density. The convective zone transports energy from the radiative zone to the surface through giant convection cells. Plasma gets heated, rises to surface, cools, and sinks back down.
