The Galaxy Cluster Abell 2151 in Constellation Hercules

The galaxy cluster Abell 2151 in the constellation Hercules, therefore also known as the Hercules cluster, has an extension of approx. 1° and is located at a distance of approx. 500 light years. Unlike other clusters, it has no central galaxy, and contains several interacting galaxy systems. It was first described by Harlow Shapley in 1933.


The Galaxy Cluster Abell 2151 in Constellation Hercules, Telescope Newton f=1000mm f/4, Camera Atik 460Exm, Total Exposure Time 13h30min

Galaxy members of the cluster include:
  • NGC 6041

  • Arp 272 (NGC 6050 und IC 1179)

  • NGC 6045 (Arp 71)

  • NGC 6034

  • NGC 6040

  • NGC 6042

  • NGC 6043

  • NGC 6044

  • NGC 6047

  • NGC 6054

  • NGC 6055

  • NGC 6056

  • NGC 6057

  • NGC 6061

Abell 2151 has lots of spiral galaxies, some of which are merging. I was particularly struck by the irregular galaxy IC 1182 in the image (upper part towards east). When I looked at it, I initially thought of a jet similar to the one of M87. However, research shows it is a tidal tail (according to, which contains stellar material. It is different from jets of active galaxies. Also noticeable are NGC 6040, which interacts with PGC 56942 (similar to M51), as well as IC 1178 and IC 1181. |

Exposure Data:
  • Newton f=1000mm f/4

  • Camera Atik 460Exm mit Baader RGB Filtern

  • Exposure Times
    • 104x300s L

    • 15x300s R

    • 16x300s G

    • 29x300s B

  • Total: 13h30min

  • Date: 09.05.-12.05.2024

  • Location: Bad Kreuznach / Germany

  • Mount Skywatcher EQ8R-pro / Pegasus Astro EQMod

  • Guiding and Exposure Control with INDI / PHD2 / CCDCiel running on XUbuntu Linux

  • Image Processing PixInsight and Darktable


The Galaxy Cluster Abell 2151 in Constellation Hercules with Galaxy Catalogue Annotation (NGC/IC), North is to the right

Another annotated image should be added here, in which quasars and their z-value, the redshift, have been entered. Just below NGC 6045 you can clearly see the quasar with the largest redshift of 3.005. This roughly corresponds to a light travel time of 11.6 billion years. |


The Galaxy Cluster Abell 2151 in Constellation Hercules with Quasar Catalogue Annotation (Milliquas, Type and Z-numbers only), North is to the right