Electronic Telegram No. 2889 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 2011hi IN IC 883 = PSN J13203538+3408222 E. Kankare, University of Turku; S. D. Ryder, Australian Astronomical Observatory; S. Mattila, University of Turku; C. Romero-Canizales, M.-A. Perez-Torres, and A. Alberdi, Instituto de Astrofisica de Andalucia, CSIC, report the discovery of an apparent supernova on near-infrared images of the luminous infrared galaxy IC 883 in the course of their follow-up of supernova 2010cu (cf. CBETs 2213, 2286), which was discovered earlier by the authors in the same host galaxy. This new object, which was designated PSN J13203538+3408222 when it was posted at the Central Bureau's TOCP webpage and is here designated SN 2011hi, was discovered in J-, H-, and K-band images obtained using NIRI and the ALTAIR laser-guide-star adaptive-optics system on the Gemini-North Telescope on 2011 Feb. 11.6 UT via comparison with images obtained with the same instrument on 2010 May 4.5 UT, well before the supernova had exploded. See the Gemini images at the following website URL: http://users.utu.fi/sepmat/ic883.jpg. The supernova was confirmed with a detection in another epoch of J-, H-, and K-band images obtained using the same instrument on 2011 Apr. 18.5 UT. Supernova 2011hi is located 0".65 east and 0".45 south of the galaxy's K-band nucleus, at R.A = 13h20m35s.387, Decl. = +34o08'21".69 (equinox 2000.0), accurate to +/- 0".3. Adopting a distance of 100 Mpc for IC 883 (z = 0.023299; Rothberg and Joseph 2006, A.J. 131, 185; and H_o = 70 km/s/Mpc), this corresponds to a projected distance of about 380 pc. Approximate discovery magnitudes for 2011hi are J = 17.9, H = 17.2, and K = 16.7; the magnitudes on Apr. 18.5 were J = 18.1, H = 17.0, and K = 16.4. The colors and absolute magnitudes are consistent with a 'slowly declining' core-collapse supernova (Mattila and Meikle 2001, MNRAS 324, 325), similar to the type-IIL supernova 1979C and the type-IIn supernova 1998S, discovered about 3 months after maximum with a low host-galaxy extinction. Alternatively, the observations might be explained by an intrinsically bright type II-P supernova discovered during the plateau phase and suffering from a host-galaxy extinction of A(V) about 7. The small offset from the luminous infrared galaxy's nucleus and possible high extinction makes any spectroscopic follow- up very difficult. Instead, high-spatial-resolution follow-up observations at infrared wavelengths are encouraged. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 November 2 (CBET 2889) Daniel W. E. Green