Electronic Telegram No. 2266 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@iau.org; cbatiau@eps.harvard.edu URL http://www.cfa.harvard.edu/iau/cbat.html SUPERNOVA 2010cl IN MCG -02-25-20 J. Maza, M. Hamuy, R. Antezana, L. Gonzalez, P. Gonzalez, S. Silva, G. Folatelli, R. Cartier, F. Forster, and S. Marchi, 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 17.1 +/- 0.3) on an unfiltered image taken on Apr. 29.01 UT with the 0.41-m 'PROMPT 4' telescope located at Cerro Tololo. The new object, which is also present at mag approximately 17.2 in an image taken on Apr. 29.99, is located at R.A. = 9h50m12s.32 +/- 0".1, Decl. = -12o03'09".2 +/- 0".1 (equinox 2000.0), which is about 24".0 west and 18".4 north of the center of the galaxy MCG -02-25-20. Nothing is visible at this position on archival images taken on Mar. 29.09 (limiting mag 18.0) and Feb. 4.13 (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 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars.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 April 30 (CBET 2266) Daniel W. E. Green