NGC 5988 is a LINER galaxy, i.e. it has a type of nucleus that is defined by its spectral line emission which has weakly ionized or neutral atoms, while the spectral line emission from strongly ionized atoms is relatively weak.[4]
One supernova has been observed in NGC 5988: SN 2023hbv (type II, mag 19.278) was discovered by ATLAS on 29 April 2023.[5]