Electronic Telegram No. 1699 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 2009ah IN ESO 171-4 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 16.0 +/- 0.2) on an unfiltered image taken on Feb. 19.22 UT with the 0.41-m 'PROMPT 3' telescope located at Cerro Tololo. The new object, which was confirmed at mag 16.1 +/- 0.2 on an unfiltered image obtained on Feb. 20.06, is located at R.A. = 11h59m12s.06 +/- 0".1, Decl. = -53o24'06".5 +/- 0".1 (equinox 2000), which is about 22".5 east and 25".8 north of the center of the galaxy ESO 171-4. Nothing is visible at this position on archival images taken on Jan. 22.23 (limiting mag 18.5) and Feb. 1.33 (limiting mag 18.0). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2009 CBAT 2009 February 20 (CBET 1699) Daniel W. E. Green