Abell 2151 – the Hercules Galaxy Cluster

Observation Notes

Abell 2151, commonly known as the Hercules Galaxy Cluster, is a rich and dynamically active cluster of galaxies located roughly 500 million light-years away in the constellation Hercules. Unlike more relaxed galaxy clusters dominated by smooth elliptical systems, Abell 2151 is notable for its chaotic structure and a high fraction of spiral galaxies, indicating that the cluster is still in the process of formation and gravitational assembly.

Deep imaging of the region reveals a dense concentration of interacting galaxies, tidal distortions, compact groups, and faint background systems spread across the field. Many member galaxies show signs of ongoing encounters and mergers, making Abell 2151 an excellent laboratory for studying galaxy evolution in dense environments.

The cluster is part of the larger Hercules Supercluster and contains numerous cataloged NGC and IC galaxies embedded. Some snapshots are shown in Rev B using the excellent SkyAnnotationStudio script by @coldt_astrophotography

Data were taken on 2026 May 15,16,17,18, and 22 (nights are short …)

Technical Details

View the full-resolution image together with complete acquisition and processing details on AstroBin.