IC 2118: The Witch Head Nebula . ... This suggestively shaped reflection nebula is associated with the bright star Rigel in the constellation Orion . More formally known as IC 2118 , the Witch Head Nebula glows primarily by light reflected from Rigel , located just outside the top right corner of the above image . Fine dust in the nebula reflects the light. The blue color is caused not only by Rigel 's blue color but because the dust grains reflect blue light more efficiently than red. ...