van den Bergh 152/Cederblad 201

About This Photograph

This enigmatic cloud of dust in the constellation of Cepheus has some interesting things going on in it. The blue patch at one end is caused by the dust reflecting the light of the bright bluish star entering the cloud, apparently as a chance encounter. The very dark area immediately to the left of this is a thick knot in the cloud which is dense enough to prevent any light from beyond from being seen. Further to the left the dust grows less dense, and we begin to see stars shining through, and the dust itself takes on a reddish, rusty color. This color is due to the fact that the the dust preferentially allows light of longer (i.e., redder) wavelengths through, while blocking light of shorter wavelengths. The source of this back lighting for the cloud is the overall light from our Milky Way galaxy.

For an interesting technical article on this field, click here.