Reflection Nebula -- Part 4 to Part 6

 The reflected nebula or reflection nebula is a cloud of dust and gas  that does not create its own light, but its light is produced by the  reflection of light coming from and around nearby stars.
Both  the dust and the gas there are thick and well lit by bright young  stars, as they are stars or stars close to those clouds and not hot  enough to cause ionizing gas or dust from that nebula, Enough to make them visible. The gas may sometimes be so thick that these new stars can not be seen with optical binoculars.
The  reflective nebula is created when the light from one or more stars is  diffused and is reflected at the nearby gas and dust clouds. The diffused light is slightly polarized and has a spectrum similar to that of bright stars and only blue

This  shift in color is due to the size of the high-carbon dust particles in  that cloud and the very thin reflect light of short wavelength more  efficiently than the longer wavelengths. As  a result, the blue light is scattered and diffused more than the longer  wavelengths, giving the characteristic blue color of this nebula. The reflected nebula is usually less dense than the dark nebula
The nebula may occur near a cooler star (such as the giant star  Antares), in which case the nebula color will be yellowish as the blue  light waves from a cold star in such a state are little and not  sufficient to propagate.
The  size of the nebula is not determined by the size of the cloud of dust  through its area of ​​presence, but rather determines the area where the  luminosity spreads through the surrounding area. Often, the reflected nebula and the evaporative nebula are sometimes shown together and are referred to as scattered sludge 

  image source   1 

 Nebula is the birthplace of stars  -- Part 1    

Planetary Nebula   -- Part 2   

Emission Nebula   -- Part 3   

Reflection Nebula   -- Part 4    The Post has been added     

Dark Nebula   -- Part 5  

Supernova Remnants   -- Part 6