Electronic Telegram No. 1299 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 2008ax IN NGC 4490 C. J. Stockdale, Marquette University and University of Oklahoma; K. W. Weiler, Naval Research Laboratory; S. Immler, Goddard Space Flight Center; S. D. Van Dyk, Spitzer Science Center, California Institute of Technology; N. Panagia, Space Telescope Science Institute and Observatory of Catania; J. M. Marcaide, University of Valencia; D. Pooley, University of Wisconsin at Madison; and R. A. Sramek, National Radio Astronomy Observatory, report the detection of radio emission near the position of the type-IIP supernova 2008ax (cf. CBET 1280) with the Very Large Array radio telescope. A flux density of 1.19 +/- 0.07 mJy was measured at 8.46 GHz (wavelength 3.5 cm) and 5.80 +/- 0.59 mJy at 22.46 GHz (wavelength 1.3 cm) on Mar. 7.54 UT. The measured position of the radio emission of R.A. = 12h30m40.s80, Decl. = +41o38'14".9 (equinox 2000.0) is in good agreement with the measured optical position (end figures 40s.84, 15".4) given on CBET 1286. Re- observation on Mar. 10.25 indicates that the flux density of the radio source has risen to 3.94 +/- 0.23 mJy at 8.46 GHz and 6.74 +/- 0.70 mJy at 22.46 GHz, indicating almost certain detection of radio emission from SN 2008ax. The inverted radio spectrum implies that the radio emission has likely been caught on the rise. Because of the unusual underluminous nature of SN 2008ax (CBET 1285) and its resemblance in some characteristics to the peculiar type- II supernova 1987A (CBETs 1285, 1290), the object warrants further study in all wavelength bands. Radio observations are continuing. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2008 CBAT 2008 March 12 (CBET 1299) Daniel W. E. Green