AS101 Lecture 4: Lesson 4 - Star formations and birth
Document Summary
Created by ejnar hertzsprung and henry noris russell. Plot of the temperature of stars along the x- axis. Begins at a star"s surface temperature of about 30,000 k decreasing down to a surface temperature of about 2000 k. Our sun has a surface temperature of 5800 k. Cool luminous stars (supergiant"s) are big while hot not-so-bright (white dwarf) are small. As we move upward along the main sequence stars get larger- somewhat. Brightest star in the sky is sirius (sirius and sirius a) The internal structure of all main sequence stars is the same. All have a core in which fusion is taking place. Fusion is the conversion of hydrogen into helium. Radiation zone surrounded by the convection zone where the heat rises to the surface and then to the photosphere. The matter that exists in the space between the star systems in the galaxy. Gas is about 75% hydrogen, 25% helium and traces of heavier atoms and molecules.
