According to A.M. Garcia, the galaxy NGC1620 is part of the NGC1589 Group (also known as LGG117) that includes at least 8 other galaxies: NGC 1586, NGC 1587, NGC 1588, NGC 1589, UGC 3054, UGC 3058, UGC 3072 and UGC 3080.[4]
^Garcia, A. M. (1993). "General study of group membership. II. Determination of nearby groups". Astronomy and Astrophysics Supplement Series. 100: 47. Bibcode:1993A&AS..100...47G.