AST 309 Midterm: Exam One Review
Document Summary
Gamma rays, x rays, uv rays (shorter than visible) Infrared (1-350 microns), microwaves, and radio waves (longer than visible) The temperature of an object determines what type of radiation it emits. Can be found by looking at where a star peaks on its curve. Wien"s law: relates the surface temperature of the star to its color. The hotter the object it is, the bluer it will appear, the cooler, the redder. Stefan-boltzmann law: luminosity relates to size and temperature. If two objects are the same temperature, the larger one is more luminous. Continuous: an array of all wavelengths or all colors of the rainbow. Formed when a solid or very dense gas gives off radiation. Absorption spectrum: dark lines within a continuous spectrum. When passing white light through a cool gas. Emission spectrum: appears as a pattern of bright lines on dark background. Before, most astronomers believed differences in spectral lines were due to differences in chemical abundance.
