Electronic Telegram No. 2964 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION CBAT Director: Daniel W. E. Green; Hoffman Lab 209; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbatiau@eps.harvard.edu (alternate cbat@iau.org) URL http://www.cbat.eps.harvard.edu/index.html Prepared using the Tamkin Foundation Computer Network SUPERNOVA 2011jo IN NGC 10 = PSN J00083457-3351148 Greg Bock, Windaroo, Queensland, Australia, reports the discovery by Stuart Parker (Oxford, Canterbury, New Zealand) of an apparent supernova (mag 18.0) on a 30-s unfiltered CCD image taken on Dec. 22.431 UT using a 35-cm F/6.3 Celestron C14 reflector (+ ST10 CCD camera). The new object is located at R.A. = 0h08m34s.57, Decl. = -33d51'14".8 (equinox 2000.0; measured by Bock using the USNO-B and UCAC3 catalogues), which is 2" east and 16" north of the nucleus of the galaxy NGC 10. Nothing is visible at this position on Digitized Sky Survey red and infrared images (limiting red magnitude > 19) or on Parker's image taken on 2011 Nov. 30 (limiting red mag 18.6). The variable was designated PSN J00083457-3351148 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2011jo based on the spectroscopic confirmation reported below. Nidia Morrell, Las Campanas Observatory; and Paulina Lira, Universidad de Chile, report that an optical spectrogram (range 363-920 nm) of PSN J00083457-3351148 = SN 2011jo, obtained with the Las Campanas 2.5-m du Pont telescope (+ WFCCD) on Dec. 28.04 UT, shows it to be a type-II supernova shortly after explosion. Cross-correlation with a library of supernova spectra using the supernova identification tool SNID (Blondin and Tonry, 2007, Ap.J. 666, 1024) yields a best match to the spectrum of the type-II-P supernova 1999em at three days before maximum brightness. Considering for the host galaxy an expansion velocity of 6811 km/s (Mathewson et al. 1992, Ap.J. Suppl. 81, 413) -- in coincidence with nebular emission from an underlying H II region present on the spectrum -- the minimum of the H_beta absorption appears blueshifted by approximately 10800 km/s. Na I absorption at the redshift of the host galaxy is observed with an equivalent width of 0.19 nm. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 December 31 (CBET 2964) Daniel W. E. Green