Diffuse Nebulae Click icon to view a diffuse nebula from Messier's catalog Messier's diffuse nebulae; Links The icon shows reflection nebulae in Scorpius around Antares. The globular cluster at the lower right is M4. Diffuse nebulae, sometimes inacurately referred to as gaseous nebulae, are clouds of interstellar matter, namely thin but widespread agglomerations of gas and dust. If they are ...
seds.org/messier/diffuse.html
Nebulae Click the icon to view Nebulae of the Messier Catalog The icon shows the Horsehead Nebula (Barnard 33), a dark nebula superimposed on an emission nebula (IC 434). Diffuse Nebulae Diffuse nebulae are clouds of interstellar matter, namely thin but widespread agglomerations of gas and dust. If they are large and massive enough they are frequently places of star formation, thus generating ...
seds.org/messier/nebula.html
Nebulae are huge, diffuse clouds of gas and dust in intergalactic space. The gas in nebulae (the plural of nebula) is mostly hydrogen.
www.enchantedlearning.com/subjects/astronomy/stars/nebulae.shtml
The HII regions (emission nebulae) are so named because they are composed mostly of a plasma of ionized hydrogen (HII) and free electrons. The hydrogen atoms of the interstellar medium are ionized by the ultraviolet radiation from a nearby star or stars.
fusedweb.pppl.gov/CPEP/Chart_Pages/5.Plasmas/Nebula/Emission.html
NSSDC Photo Gallery: Nebulae - A collection of images of astronomical nebulae ...
nssdc.gsfc.nasa.gov/photo_gallery/photogallery-astro-nebula.html
Fusion - Physics of a Fundamental Energy Source Nebulae Fuzzy Patches in Space Photo Credit: NGC 2440, Hubble Space Telescope The term nebula was originally used by astronomers to refer to any fuzzy' patch in the sky that could be easily distinguished by a telescope, but was not sharp like stars or planets. Charles Messier, an eighteenth century French astronomer, published his famous catalogue ...
fusedweb.pppl.gov/CPEP/Chart_Pages/5.Plasmas/Nebula.html
Wonderful Pictures of Galactic and Planetary Nebulae, Images of 110 Astronomical Nebulas, Reflection Emission and Dark Nebula Photos ...
www.biochem.szote.u-szeged.hu/astrojan/nebula1.htm