The Pleiades, also known as the Seven Sisters and cataloged as Messier 45 (M45), is a prominent star cluster mentioned in the Old Testament of the Bible, appearing in Amos 5:8, Job 9:9, and Job 38:31. The cluster is dominated by hot, blue, luminous stars that formed within the last 100 million years.

The reflection nebulae surrounding the brightest stars were once believed to be remnants of their formation but are now thought to be an unrelated dust cloud in the interstellar medium through which the stars are currently passing. This dust cloud is estimated to be moving at approximately 18 km/s relative to the cluster.