APOD 3.2

Hidden Treasures of M78 (27 January 2011)

This apod shows a picture of M78. It is about 1,600 light-years away and is located in the the constellation Orion. This is a large, bright, and well known reflection nebula. The blue seen in this nebula is caused by the reflection of wavelengths which is why it is a reflection nebula. When interstellar dust grains are near a bright star, clouds of these dust particles scatter short wavelengths of visible starlight more readily than long wavelengths. This produces the blue color that is seen in the nebula. There are many more examples of reflecting nebulae like the Iris Nebula (NGC 7023) and the Witch Head (IC2118). 
This picture was taken by Igor Chekalin who won the Hidden Treasures 2010 astrophotography competition held by the European Southern Observatory. Seeing this photograph and the other photos that were entered, it's amazing what these amateur astronomers could do.
Also in this picture, in the bottom right, is McNeil's Nebula. It has a yellowish color and was apparently discovered by an amateur astronomer, Jay McNeil who was testing out his new telescope by focusing on the area around M78. The story behind the discovery of McNeil's Nebula was interesting to read because I would assume that other professional astronomers with access to observatories and high tech equipment would have already discovered it long ago.