TYPE OF NEBULA

The omega nebula, an example of an emission nebula

 

 The Horsehead Nebula, an example of a dark nebula

 

The cats Eye Nebula, an example of a planetary nebula

 The Crab Nebula, an example of a supernova remnant

 The Red Rectangle Nebula, an example of a protoplanetary nebula

# credit: http://en.wikipedia.org/wiki/Nebula