messier objects
from a catalog of nebulae
"what aren't comets"

flammarion
uranie
lumen

I have a copy of Lumen

nebula
1655–65; < L: a mist, vapor, cloud; akin to Gk nephélē cloud, G Nebel fog, haze

nebulous
resembling a nebula

1. hazy, vague, indistinct, or confused: a nebulous recollection of the meeting; a nebulous distinction between pride and conceit.
2. cloudy or cloudlike.