An irregularly shaped cloud of interstellar gas or dust.
Diffuse nebulae are clouds of dust and gas in interstellar space, several light years across. Stars are formed when diffuse nebulae collapse under the influence of gravity, compressing and heating until nuclear fusion begins, igniting a new-born star. Diffuse nebulae can be further broken down into emission nebulae and reflection nebulae. You can find more information at The Columbia Encyclopedia. Be sure to check out some spectacular Hubble Space Telescope photos of nebulae.
Diffuse or "fuzzy" appearing clouds of interstellar gas and dust. Diffuse nebulae can include both bright ( emission and reflection) and dark nebular components.
A cluster of stars within a cloud of gas and dust.
A wide, irregularly-shaped cloud of gas that can be up to 100 light-years across.
an emission or reflection nebula
A cloud of ionized gas, mostly hydrogen, with an emission-line spectrum.
In astronomy, diffuse nebulae is the general term for illuminated nebulae. The three types of diffuse nebulae are reflection nebulae, emission nebulae and supernova remnants. They are diffuse as opposed to the non-diffuse dark nebulae, i.e. the particles have spread out.