Deep-sky objects (or DSOs) are astronomical objects that are not individual stars or Solar System objects (for example the Sun, planets, etc). Astronomers usually talk about DSOs when referring to star clusters, nebulea and galaxies.
Crab nebula (M1)
Iris nebula (NGC 7023)
Ring nebula (M57)
North America nebula (NGC 7000)
North America nebula (NCG 7000)