Electronic Telegram No. 1758 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) CBAT@CFA.HARVARD.EDU (science) URL http://www.cfa.harvard.edu/iau/cbat.html SUPERNOVA 2009da G. Pignata, J. Maza, M. Hamuy, R. Antezana, L. Gonzalez, P. Gonzalez, P. Lopez, S. Silva, G. Folatelli, D. Iturra, R. Cartier, F. Forster, and S. Marchi, Universidad de Chile; B. Conuel, Wesleyan University; and D. Reichart, K. Ivarsen, 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 16.9 +/- 0.3) on unfiltered images taken on Apr. 7.40 and 8.39 UT with the 0.41-m 'PROMPT 3' telescope located at Cerro Tololo. The new object is located at R.A. = 21h42m07s.20 +/- 0".1, Decl. = -6o46'25".6 +/- 0".1 (equinox 2000.0), which is about 12".6 west and 4".2 north of center of the apparent host galaxy. Nothing is visible at this position on archival images taken on 2008 Oct. 17.10 and 26.02 (limiting mag 18.5). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2009 CBAT 2009 April 8 (CBET 1758) Daniel W. E. Green