Quick explanation
A spectrum is an image, or a graph, of the distribution of the wavelengths of some light.
By looking at the spectrum of e.g. a star or a galaxy, you can learn incredibly much about the object's chemical composition, temperature, motion, and much, much more.
This article is a stub.
The encyclopedia is being re-constructed; until I fix it, you'll have to
- do with the short version, or
- read one of the articles I did finish (the ones on the front page with colored icons), or
- read the Danish version, or
- Make me finish it.
