White light is made up of a rainbow of colors. We see this effect every time light hits a prism and turns into a rainbow.
A spectroscope is a device that breaks up the light from a single object into its component colors, allowing scientists to analyze the light and discover properties of the object emitting it.
In a spectrum, patterns of bright or dark areas, or lines, indicate the emission of absorption of light by particular atoms and molecules present in stars and nebulae. By studying the patterns, widths, strengths and positions of these lines we can also determine:
- State (is the element present in the form of molecules, atoms, or ions)
- Speed (toward or away from us)
- Distance (if in a distant galaxy)