A magnitude 13.8 type II supernova was discovered on the 7th January, 2012, in the irregular galaxy NGC 3239(Arp 263), in the constellation Leo, by J. Newton, T. Puckett and B. Moore (Apache Point Observatory). The supernova is located 24.65" east and 16.1" south from the center of the galaxy. Position (2000): RA 10 25 07.38 | Dec +17° 09' 14.6"