cluster · M45
Pleiades
The most famous star cluster in the sky, the Pleiades are only 444 light-years away and have been observed by virtually every human culture throughout history. The cluster contains over 1,000 confirmed members, the brightest of which are hot blue B-type stars around 100 million years old. The wispy blue reflection nebulosity visible around the stars is a chance encounter with an unrelated interstellar dust cloud the cluster is passing through, not the remnant of the stars’ birth cloud.