M45 is a brilliant example of an open star cluster. The bright gouping contains more than 300 stars in total, though only about a dozen are visible to the unaided eye. Even more striking than the cluster, however, is the delicate cirrus-like structure of the surrounding reflection nebulosity. Despite first impressions, this dusty nebula is not directly associated with the birth of the star cluster itself. Rather, the cluster members are apparently traveling through a nearby cloud of gas and dust. This image, taken on November 18, 2008 was exposed for a total of 2 hours. The camera was an SBIG STL11000m and the telescope used was a Takahashi FSQ-106 Refractor. You can click on the image above to see it at full scale.