ASTRON C10 Lecture Notes - Lecture 4: Redshift
ASTRON C10 verified notes
4/19View all
Document Summary
8:30 - 10:00 monday - wed. campbell hall 6th floor star viewing. Doppler effect: can tell you radial velocity of an object; speed the object moves away from us in the line of sight. Wave crests bunch up in direction of motion. When dealing with light, only the relative motion matters. Doppler shift: v <= 0. 2c is a good approximation. Hot stars are blue; more bouncing around; emit shorter-wavelength radiation. Cool stars are red; emit longer-wavelength radiation. A star"s spectrum is that of a thermal emitter--no transmitted or reflected light ( blackbody ) Planck curves - as we move to hotter temperatures, area under the curve increases. Wien"s law: peak wavelength * temperature = constant = 2. 9 * 10^6 nm-k. Humans are visible optically bc of reflected light.
