Coma Star Cluster
About this object
The Coma Star Cluster (Melotte 111), nestled in the constellation Coma Berenices, is one of the closest and most graceful open clusters in the sky. Located just 285 light-years from Earth, this 445-million-year-old stellar gathering spans over 5 degrees on the sky — nearly 10 full moons wide — making it a stunning binocular target for dark-sky observers.
Comprising around 40–50 loosely bound stars, Melotte 111 glows at an integrated magnitude of +1.8, dominated by F- and G-type stars that gently arc through the spring skies. Though sparse compared to dense globulars, its members share a common proper motion and radial velocity, identifying them as remnants of a once-tighter cluster slowly dissolving into the galactic disk.
With a metallicity near solar ([Fe/H] ≈ 0.0) and low stellar density, it offers a living laboratory for studying stellar evolution in older open clusters. Though it lacks the crowding of globulars like M13, its proximity, age, and wide angular extent make it a cornerstone of kinematic and chemical surveys. As part of the Local Association (Pleiades moving group), the Coma Star Cluster represents the quiet beauty of stellar adolescence — a stellar family gently drifting apart under the slow churn of the Milky Way.
Designations
Standardized Catalogues
Melotte 111
PMC Observatory Catalogue
Observations
2025-08-04 at around 11:00 pm +01:00
Photographs
