NGC 5806 contains a star that was catalogued as a supernova (SN Hunt 248), but turned out to be a supernova imposter. The progenitor was detected as a cool hypergiant with an absolute visual magnitude of −9 and 400,000 times more luminous than the sun. The eruption saw it increase in luminosity to around 80,000,000 L☉.[5]
NGC 5806 has also hosted several true supernova. SN 2004dg, around 100 times brighter than SN Hunt 248 was a typical type II supernova. The progenitor has not been detected and is expected to have been a relatively low mass, low luminosity, red supergiant.[6]PTF12os in 2012 was a type IIb supernova that occurred in 2012, and iPTF13bvn was a type Ib supernova that exploded in 2013.[7]