Electronic Telegram No. 2673 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 2011ar IN UGC 2509 = PSN J03032521+0429399 [NOTE: This replaces the text on CBET 2672 (designation).] Further to CBET 2671, M. Kandrashoff, S. B. Cenko, W. Li, and A. V. Filippenko report the LOSS discovery of an apparent supernova on unfiltered KAIT images: SN 2011 UT R.A. (2000.0) Decl. Mag. Offset 2011ar Jan. 27.20 3 03 25.21 + 4 29 39.9 19.0 15".1 E, 8".9 N The variable was designated PSN J03032521+0429399 when posted on the Central Bureau's TOCP webpage and is designated SN 2011ar here based on the spectroscopic report below. Additional KAIT magnitudes for 2011ar in UGC 2509: a co-added frame from Dec. 2010 to Jan. 2011, [20.3; 2011 Jan. 28.19 UT, 19.2. J. M. Silverman, S. B. Cenko, and A. V. Filippenko, University of California, Berkeley, report that inspection of a relatively noisy CCD spectrum (range 330-1000 nm), obtained on Mar. 9 UT with the 10-m Keck I telescope (+ LRIS), shows that PSN J03032521+0429399 = 2011ar is a type-II supernova. After removal of the host-galaxy recession velocity of 5860 km/s (measured from narrow host-galaxy emission lines), they find the absorption minimum of the H-alpha line to be blueshifted by about 7150 km/s. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 March 11 (CBET 2673) Daniel W. E. Green