Supernova 2012bw in UGC 10282 = Psn J16125609+3230423

Report the discovery of an apparent supernova in public images from the Catalina Sky Survey (CSS). SN 2012 UT R.A. (2000.0) Decl. Mag. Offset 2012bw Mar. 22.44 16 12 56.09 +32 30 42.3 19.0 19".0 W, 2".6 S Nothing was visible at this position on an image from Apr. 2.45 UT (limiting mag 20.0). The variable was designated PSN J16125609+3230423 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2012bw based on the spectroscopic confirmation reported below. L. Tomasella, S. Benetti, E. Cappellaro, P. Ochner, A. Pastorello, M. Turatto, and S. Valenti, Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica, obtained a spectrogram of 2012bw on Apr. 25.06 UT with the Asiago 1.82-m Copernico Telescope (+ AFOSC; range 340-820 nm; resolution 2.4 nm). The extracted spectrum, heavily contaminated by narrow emission lines likely originating from a nearby H II region, suggests that this is a type-Ic supernova near maximum. Cross-correlation with a library of supernova spectra via the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows that, assuming a redshift of z = 0.0309 for the host galaxy (average of different estimates listed in the NASA/IPAC Extragalactic Database), 2012bw is similar to several type-Ic supernovae near maximum at a redshift z = 0.031. The redshift coincides with the redshift of the host galaxy, UGC 10282 (average of different estimates listed in the NASA/IPAC Extragalactic Database).