Similar to IOK-1
NGC 53
NGC 53NGC 54
NGC 54NGC 57
NGC 57NGC 59
NGC 59NGC 60
NGC 60NGC 63
NGC 63NGC 88
NGC 88NGC 89
NGC 89
NGC 247
NGC 247NGC 474
NGC 474NGC 520
NGC 520NGC 625
NGC 625NGC 634
NGC 634NGC 772
NGC 772
NGC 1073
NGC 1073NGC 1087
NGC 1087NGC 1234
NGC 1234NGC 1260
NGC 1260
NGC 1313
NGC 1313NGC 1512
NGC 1512NGC 1600
NGC 1600NGC 1637
NGC 1637NGC 1705
NGC 1705NGC 2442/2443
NGC 2442 and NGC 2443NGC 2770
NGC 2770NGC 2775
NGC 2775
NGC 2787
NGC 2787NGC 2903
NGC 2903