First Evidence of an Active Galactic Nucleus
The first optical spectrum of what we now would call an AGN was obtained by E. A. Fath
at the Lick Observatory in 1908. While a graduate student, he studied the Sb spiral
galaxy NGC
1068, which lies at a distance of about 18 Mpc in
Cetus and is also listed in the Messier catalog as M77. Fath found that NGC 1068
exhibited a very unusual feature for a galaxy:
strong emission lines. Although the full implication
of these emission lines was not
appreciated for more than half a century, we now know that NGC 1068 is a kind of active
galaxy called a Seyfert galaxy, and that this is the reason it has emission lines.