M45

Constellation: Taurus

Distance: 444 light-years

The Pleiades star cluster (M45) consists of about 500 stars spread of 14 light-years of space. At least 7 of its stars are visible to the naked eye (hence the name Seven Sisters in Greek mythology), roughly forming the shape of a small "dipper" and therefore sometimes mistaken for the "Little Dipper" by the uninitiated. The tightness of the cluster is an indicator of its youth, probably on the order of 100 million years (about 1/50th the age of our sun).

Like all open clusters, the member stars are of the same age, same composition, same distance from earth and moving in the same approximate direction and speed (in the case of M45, about 40 kilometers per second). However, unlike most star clusters that illuminate the surrounding nebula from which they were born, the blue reflection nebula surrounding M45 is moving at a different radial speed than the stars, and is therefore not related. Rather, the star cluster has serendipitously wandered into an unrelated molecular cloud with which it is interacting.

Here are 2 prior attempts at this object:

9/22/06, North Branch, NY

Canon 350D Modified, 200 mm f2.8 lens with 2X extender (400mm FL, f5.6)

9/11/05, North Branch, NY

200 mm focal length