Open cluster in Scorpius. 

Messier 6 is a group of several hundred stars about 1600 light years away.  Many open clusters can resemble everyday objects if you use a little imagination, and looking through a telescope with a wide-field eyepiece it is pretty easy to see the butterfly pattern in Messier 6.  I have probably shown this cluster to hundreds of children at various public observing events, and when I ask them if they can find the butterfly pattern, most of them see it immediately. 

Messier 6 is also a nice showpiece because it includes a variety of star colors.  Most of the stars are white or blue-white, but a few are yellow or orange.  In fact, the brightest star in the cluster, the variable star BM Scorpii on the edge of the butterfly’s left wing, has a distinct orange color.

Image details:  9 images, each 60 seconds at ISO 1600, taken with a Canon 400D camera through a Meade 12” telescope at f/6.8.  Image processing with ImagesPlus and Photoshop.

July 2010