Electronic Telegram No. 1280 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 POSSIBLE SUPERNOVA IN NGC 4490 Further to CBET 1276, R. Mostardi, W. Li, and A. V. Filippenko, University of California at Berkeley, report the LOSS discovery of a possible supernova (mag 16.1) on unfiltered KAIT images taken on Mar. 3.45 and 4.39 UT. The variable is located at R.A. = 12h30m40s.80, Decl. = +41o38'14".5 (equinox 2000.0), which is 53".1 east and 25".8 south of the center of NGC 4490. Nothing was visible at this position on KAIT images taken on Feb. 8.47 (limiting mag 18.9) and 19.45 (limiting mag 18.0). Given the distance to NGC 4490, and assuming that the variable is associated with that galaxy, the variable an apparent absolute magnitude of only about -13.4, suggesting either (a) a highly reddened and/or low-luminosity supernova or (b) the super-outburst of a luminous blue variable such as SN 1997bs (Van Dyk et al. 2000, PASP 112, 1532). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2008 CBAT 2008 March 4 (CBET 1280) Daniel W. E. Green