Abell Galaxy Clusters

Galaxy clusters, held together by the force of gravity, are among the largest cosmic structures known. Exerting a mutual pull, the far-flung galaxies in a cluster can extend many millions of light-years across space.

Between 1996 and 1998 I observed 28 galaxy clusters from the Abell catalog. The observing program will be resumed now for the clusters not yet observed (see the "To Do Cluster List" below). 

Observations:

distance class 1
- AGC 194 Cet
- AGC 262 And
- AGC 347 And
- AGC 426 Per
- AGC 1228 UMa
- AGC 1656 Com
- AGC 2147 Her
- AGC 2199 Her
distance class 2
- AGC 1185 UMa
- AGC 1213 UMa
distance class 3
- AGC 71 And
- AGC 102   Cet
- AGC 240 Psc
- AGC 277 Cet
- AGC 278 Tri
- AGC 376 Per
- AGC 553 Aur
- AGC 568 Gem
- AGC 634 Lyn
- AGC 757    UMa
- AGC 1016 Leo
- AGC 1257 UMa
- AGC 1904 Boo
- AGC 2065 CrB
- AGC 2247 UMi
- AGC 2256 UMi
distance class 4
- AGC 193 Psc
distance class 5
- AGC 1143 UMa

To Do Cluster List (coming soon...)

- AGC 76 Psc
- AGC 119 Cet
- AGC 147 Cet
- AGC 189 Cet
- AGC 260 Tri
- AGC 539 Ori
- AGC 569 Lyn
- AGC 592 CMi
- AGC 779 Lyn
- AGC 1367 Leo
- AGC 1377 UMa
- AGC 2151 Her
- AGC 2162 CrB
- AGC 2197 Her
- AGC 2572 Peg
- AGC 2593 Peg
- AGC 2626 Peg
- AGC 2634 Peg
- AGC 2657 Peg
- AGC 2666 Peg

Explanation:

Distance class: Cluster distances, needed to determine counting radii, were estimated solely from the magnitude of the 10th brightest galaxy. This procedure was adopted to provide consistency with Abell's northern survey, and also as a matter of expediency.

Distance class 1 = magnitude of tenth brightest galaxy: < 14.0 mag 

Distance class 2 = magnitude of tenth brightest galaxy: < 14.8 mag 
Distance class 3 = magnitude of tenth brightest galaxy: < 15.6 mag 
Distance class 4 = magnitude of tenth brightest galaxy: < 16.0 mag 
Distance class 5 = magnitude of tenth brightest galaxy: < 17.2 mag