Abell 2640 cluster
Abell 2640 is a galaxy cluster from Abell's Catalog of Rich Clusters of Galaxies. This is a list of 5,000 galaxy clusters (for both northern and southern skies) having at least 30 galaxy members per cluster. Here are the key stats for Abell 2640:
NOTE: Clusters with an S suffix denote that it is located in the southern hemisphere.
| Abell #: | Abell 2640 |
| Avg cluster magnitude: | 16.7 |
| Distance class: | 5 |
| Richness class: | 1 |
| B-M class: | III |
| RA (decimal format): | 23.675 |
| Dec (decimal format): | 19.65 |
Abell Distance Class
A number 1-7 where a higher number indicates fainter and more distant clusters:
Group 1: mag 13.3-14.0
Group 2: mag 14.1-14.8
Group 3: mag 14.9-15.6
Group 4: mag 15.7-16.4
Group 5: mag 16.5-17.2
Group 6: mag 17.3-18.0
Group 7: mag > 18.0
Abell Richness Class
A number 0-5 indicating the size of the cluster - the more galaxies the richer the cluster:
0 = 30-49 member galaxies
1 = 50-79 member galaxies
2 = 80-129 member galaxies
3 = 130-199 member galaxies
4 = 200-299 member galaxies
5 = > 300 member galaxies
Bautz Morgan (B-M) Class
A measure of the contrast in brightness between the brightest galaxy of the cluster and the other cluster members, where I means a very bright centrally dominant (cD) galaxy and III indicates no bright cD galaxy.