galaxy - Active Galaxies - Astronomy

Yes of course, there are other forms apart from the four stated above. Basically you have just two kinds:

1. the radio-quiet, and


2. the radio-loud.

But then again, there are two Seyferts

1. Seyfert I, and


2. Seyfert II

Apart from Quasar, Blazar and Radio galaxy, we also have presently,

1. BL Lac (Named after its prototype BL Lacarte (original member of Blazar type)), and


2. OVV (Optically Variable Violent Quasar or OVV Quasar; subtype of Blazar)

Best source to begin with is wikipedia.org of course.