 NGC 3184 houses a high abundance of heavy elements and (SN 1999gi) that was a magnitude 14 Type II supernova detected on December 9, 1999.Other supernovae in NGC 3184 include 1921B (mag 13.5), 1921C (mag 11) and 1937F (mag 13.5).On May 31, 2010, Koichi Itagaki detected a magnitude 17 optical transient 33" east and 61" north of the center of NGC 3184 at coordinates 10 18 19.89 +41 26 28.8.