According to the SIMBAD database, NGC 213 is an Active Galaxy Nucleus Candidate, i.e. it has a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that this luminosity is not produced by the stars.[3]
One supernova has been observed in NGC 213: SN2020bqm (typeIa, mag. 18.4).[4]