ASTR 101 Lecture Notes - Lecture 6: Continuous Spectrum, Energy Level

• School: Queen's University
• Department: Physics, Engineering Physics and Astronomy
• Course: ASTR 101
• Professor: Majd Abdelqader

Document Summary

Energy level transitions: the only allowed changes in energy are those corresponding to a transition between energy levels. Chemical fingerprints: each type of atom has a unique spectral fingerprint, observing the fingerprints in a spectrum tells us which kinds of atoms are present. Energy levels of molecules: molecules have additional energy levels because they can vibrate and rotate. Thermal radiation: nearly all large or dense objects emit thermal radiation, including stars, planets, you, an objects thermal radiation spectrum depends on only one property: its temperature. Hotter objects emit more light at all frequencies per unit area. Hotter objects emit photons with a higher average energy. By carefully studying the features in a spectrum we can learn a great deal about the object. Continuous spectrum of visible light is like the suns except that some of the blue light has been absorbed- object must look red. Absorption line are the fingerprint of co2 in the atmosphere.