[00:00]	Absorption and Emission
[00:01]	Visible Light
[02:58]	Continuum, Absorption & Emission Spectra
[12:51]	Galaxy Images
[13:22]	Properties of Stars

Learning Objectives

1. Relate the color of an object to the energy that it is emitting or reflecting.

2. Describe the source and appearance of three types of spectra.
   1. Continuum spectra, where a continuous distribution of light is emitted by the cores of stars
   2. Absorption spectra, where key wavelengths of light are removed from core continuum spectra by the atmospheres of stars or by cool clouds of gas
   3. Emission spectra, where light absorbed at key wavelengths from continuum spectra are reflected in a random direction from a cool cloud of gas

3. Connect one- or two-dimensional images of spectra to the emission or absorption of light within atoms in an object (such as a star).

4. Separate the intrinsic properties (luminosity, temperature, radius, chemical composition) of stars from the apparent property (observed brightness), which varies with distance.