I found the picture below in an answer to the post "[Was the Milky Way ever a quasar][1]". The picture is published on a website belonging to "NASA/IPAC Extragalactic Database". In the answer that has 16 "thumbs up" it says: > A quasar is simply an active galactic nucleus (AGN) that is viewed > from a particular angle; see the picture below, in which quasars are > labeled "QSO". This is really a remarkable figure because historically > all of the names in the figure were thought to correspond to different > types of objects, when really they all refer to the same thing!  1. Does the picture represent the mainstream view among astronomers today or is it more like a private opinion of someone? 2. According to Wikipedia, ten percent of all observed galaxies are classified as [Seyfert galaxies](https://en.wikipedia.org/wiki/Seyfert_galaxy). Would we perceive all of those as "quasars" if we happend to observe them from the right angle? (Maybe there is also a luminosity requirement) 3. According to Wikipedia [Markarian 231](https://en.wikipedia.org/wiki/Markarian_231) is the closest quasar at a distance of 581 million light years. Also according to Wikipedia, the [Circinus Galaxy](https://en.wikipedia.org/wiki/Circinus_Galaxy) is the closest Seyfert galaxy, only 13 million light years away. Would we perceive there to be many quasars closer than 581 million light years away, if we just happend to view the active galaxy from the right angle? [1]: https://astronomy.stackexchange.com/questions/1651/was-the-milky-way-ever-a-quasar