Astronomy 1021 Lecture Notes - Lecture 7: Gigapixel Image, Optical Aberration, Spectral Resolution

• School: Western University
• Department: Astronomy
• Course: Astronomy 1021
• Professor: Robert Cockcroft

Document Summary

Contains two supernova: tycho brahe"s and cas a. If views from alpha centauri, sun would be cassiopeia. Almost all continuous spectra are due to thermal radiation. Thermal radiation is radiation that only depends on temperature. Continuous spectra is caused by blackbody radiation (i. e. thermal radiation) Looking at the brightness (or intensity) of continuous spectra can give us information about the average temperate of an object. Hotter objects emit more light per unit area at all frequencies (stefan-boltzmann law) Intensity peaks at shorter wavelengths (consequence of wien"s law. 7000 k star: more blue light than a red light, gives the star a more blue colour. 6000 k star: not too much blue or red: will appear white. 5000 k star: more red light than blue, gives this star a more red colour. Wien"s law can be seen on earth in reality. E. x. when heating iron to high temperature: first glows red, then orange, yellow and then bright white.