Electronic Telegram No. 57 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://cfa-www.harvard.edu/iau/cbat.html SUPERNOVA 2004C IN NGC 3683 C. C. Dudley and J. Fischer, Naval Research Laboratory, report the discovery of a new point source (mag K' about 14) in NGC 3683 observed with the U.S. Naval Observatory 1.55-m telescope (+ 2.1-micron K' filter + ASTROCAM 1024x1024 ALADDIN InSb imager) on at Flagstaff on Jan. 12.5 UT. The position of the source is R.A. = 11h27m29s.72 Decl. = +56o52'48".2 (equinox 2000.0), based on positions of three 2MASS stars, which is 17" west and 10" north of the K' nucleus of NGC 3683. The source shows no perceptible drift over 8 min (seeing about 1") and was not present on 2003 May 18, the most recent prior observation with ASTROCAM. T. Matheson, P. Challis, and R. Kirshner, Harvard-Smithsonian Center for Astrophysics, report that a spectrum (range 370-750 nm) of SN 2004C, obtained by P. Berlind on Jan. 15.51 UT with the F. L. Whipple Observatory 1.5-m telescope (+ FAST spectrograph), shows it to be a type-Ic supernova, similar to SN 1990U about three weeks past maximum (see Matheson et al. 2001, A.J. 121, 1648). The spectrum is highly reddened and shows a strong, narrow Na I D absorption at the velocity of the host galaxy with an equivalent width of 0.3 nm. The dust maps of Schlegel et al. (1998, Ap.J., 500, 525) indicate a low value for Galactic reddening of E(B-V) = 0.015. NOTE: These 'Central Bureau Electronic Telegrams' are intended to be preliminary announcements of items that later appear in the formal IAU Circulars. Citations should normally be made to IAUCs rather than to CBETs. (C) Copyright 2004 CBAT 2004 January 15 (CBET 57) Daniel W. E. Green