ASTRO 142 Lecture Notes - Lecture 5: Red Giant, Ideal Gas Law, White Dwarf
Document Summary
Less massive stars burn their fuel slowly and live longer. Stars are a fundamental aspect of the cosmos. Interstellar gas is the raw material from which stars form. Matter between stars is known as the interstellar medium. Nuclear reactions in the core define a star. Brown dwarfs are just below the required mass for stellar ignition. Disks are difficult to detect even for close stars. Findings suggest that planetary systems are relatively common. Stars remain in balance between inward-directed gravity and outward-directed pressure knowns as hydrostatic equilibrium. Nuclear reactions make possible the long lives of the stars. Calculations show larger the total mass of the star, the greater the central pressure. Ideal gas law tells us that the more massive the star, the higher the central pressure, the hotter it must be at its core. Hr diagram reveals relationships between stellar temperature and luminosity.
