NGC 6684 is a lenticular galaxy, disk-shaped  but without the spiral arms of galaxies like the Andromeda Galaxy or our Milky Way. Thus, lenticular galaxies are somewhere between elliptical galaxies and spiral galaxies, often with a diffuse, ghostly look. NGC 6684 also lacks the dark dust lanes that thread through other galaxies, adding to its hazy appearance.

Image Credit: NASA / ESA