Pleiades

The Pleiades, also known as Messier 45 or the Seven Sisters, is one of the most famous open star clusters in the night sky. Located in the constellation Taurus, it lies approximately 440 light-years from Earth and contains more than a thousand stars, with its brightest members easily visible to the naked eye.

The delicate blue glow surrounding the cluster is not an emission nebula but a reflection nebula. Tiny dust particles scatter and reflect the light of the young, hot stars, creating the characteristic blue wisps and filaments seen throughout the region. While these dust clouds were once thought to be remnants of the cluster’s formation, astronomers now understand that the Pleiades are currently passing through an unrelated interstellar dust cloud.

At roughly 100 million years old, the cluster is relatively young by cosmic standards. The combination of brilliant blue stars and intricate reflection nebulosity makes the Pleiades one of the most beautiful and widely photographed deep-sky objects in the northern hemisphere.