APOD 3.9 Stars, Dust and Nebula in NGC 2170

This week's picture is of NGC 2170, a star forming region in the constellation of Monoceros. You can see the red glow of emission nebulas, blue reflection nebulas, and dark absorption nebulas. The red is due to hydrogen, the blue is because of reflection from the dust, and the dark absorption nebulas are also due to the dust. Over time all the dust will blow away and an open cluster will be left, full of young hot stars. The blue stars in the picture are examples of these newly formed stars.