[4] and confirmed by several sources, including the Palomar Transient Factory.

[5] A candidate progenitor was detected in Hubble Space Telescope images.

[6] The supernova peaked near apparent magnitude 12.1 on 19 June 2011.

[8] Emission spectra indicated that the explosion was a type II supernova, in which a massive star collapses once nuclear fusion has ceased in its core.

[10] The supernova frequency in the Milky Way is estimated to be around one event every 40 years.