One of the most enigmatic stars known. It is an S Doradus-type eruptive variable, situated at the heart of the bright diffuse nebula NGC 3373. It is obscured by the Homunculus Nebula, a bright cloud of gas and dust ejected by the star itself during a major outburst in 1843, when it reached an apparent magnitude of −0.8, becoming temporarily brighter than all other stars except Sirius