Electronic Telegram No. 2174 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION CBAT Director: Daniel W. E. Green; Room 209; Dept. of Earth and Planetary Sciences; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbat@cfa.harvard.edu; dwe_green@eps.harvard.edu URL http://www.cfa.harvard.edu/iau/cbat.html SUPERNOVA 2010ac IN IC 4352 J. Maza, M. Hamuy, R. Antezana, L. Gonzalez, P. Gonzalez, P. Lopez, S. Silva, G. Folatelli, R. Cartier, F. Forster, S. Marchi, and A. Rojas, Universidad de Chile; G. Pignata and M. Cifuentes, Universidad Andres Bello; B. Conuel, Wesleyan University; and D. Reichart, K. Ivarsen, J. Haislip, A. Crain, D. Foster, M. Nysewander, and A. LaCluyze, University of North Carolina at Chapel Hill, on behalf of the CHASE project, report the discovery of an apparent supernova (mag approximately 16.6 +/- 0.4) on an unfiltered image taken on Feb. 13.31 UT with the 0.41-m 'PROMPT 5' telescope located at Cerro Tololo. The new object, which is also present at mag approximately 16.8 in an image taken on Feb. 14.26, is located at R.A. = 13h58m24s.35 +/- 0".1, Decl. = -34o30'55".4 +/- 0".1 (equinox 2000.0), which is about 9".5 west and 6".6 north of center of the galaxy IC 4352. Nothing is visible at this position on archival images taken on 2009 May 12.18 (limiting mag 18.0) and Aug. 4.04 (limiting mag 18.5). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2010 CBAT 2010 February 15 (CBET 2174) Daniel W. E. Green