AST-A 105 Study Guide - Midterm Guide: Kelvin, Photon, Uy Scuti
Document Summary
Light- the story so far: there is visible and invisible light = electromagnetic radiation, visible light tiny portion of em spectrum. Important because allows us to get the temperatures of stars. If something appears, for example orange, it does not necessarily mean that it emits light at only one wavelength, but merely that most of light intensity is around that color. What factor of temperature increase is needed for the peak to enter the ultraviolet region?---2x. Temperature and peak wavelength: simple formula, peak wavelength (nm) = 3,000,000/ temperature, human body : 300k, peak wavelength = 10,000 nm, look at spectrum to find which light corresponds. Infrared: region around black hole: 3,000,000 k, peak wavelength = 1 nm, x-ray. What produces visible light: thermal process, emission exists at all wavelengths, continuous spectrum, atomic process, emission exists only at certain wavelengths, emission line spectrum.
