M107 — The Crucifix Cluster

M107 — The Crucifix Cluster

Known for generations as the Crucifix Cluster, M107 has earned a nickname that isn't immediately obvious. At first glance it appears to be another beautiful but loosely concentrated globular. Look a little longer, however, and a broad cruciform begins to emerge from the heart of the cluster.

Rather than a thin cross traced by individual stars, I see a wider, rounded structure formed by the cluster's own stellar density. The luminous core becomes the center of that shape, while the brighter bands of stars extend outward like the broad arms of an ancient crucifix. The illustration accompanying this post highlights the pattern that caught my eye—not as proof of what must be seen, but as a guide to the historical nickname that observers have associated with M107 for generations.

Discovered by Pierre Méchain in 1782 and later added to Charles Messier's catalog, M107 lies about 20,000 light-years away in the constellation Ophiuchus. It spans roughly 80 light-years and contains hundreds of thousands of ancient, metal-poor stars that have remained gravitationally bound for billions of years.

Whether you immediately see the cruciform or simply admire a loose, richly textured globular, M107 rewards a patient eye. Sometimes an old nickname makes perfect sense—once you know where to look.