Electronic Telegram No. 676 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 2006jc IN UGC 4904 M. Modjaz, S. Blondin, R. Kirshner, and P. Challis, Harvard-Smithsonian Center for Astrophysics; and T. Matheson, National Optical Astronomy Observatory, report that a spectrogram (range 350-740 nm) of SN 2006jc, obtained by E. Mamajek on Oct. 17.50 UT with the F. L. Whipple Observatory 1.5-m telescope (+ FAST), shows it to be a peculiar supernova probably of type Ic with emission lines of He I, confirming the identification by Crotts et al. (CBET 672) and by Benetti et al. (CBET 674). The spectrum is similar to that of SN 1999cq (Matheson et al. 2000, A.J. 119, 2303); however, notable differences from SN 1999cq include a very blue continuum; additional emission lines consistent with He I 388.9-, 447.1-, and 501.5-nm (rest) that have widths of 1500-6500 km/s (FWHM); and the absence of the broad peak at around 540 nm. A plot showing the comparison between 2006jc and 1999cq can be viewed via the webpage http://cfa-www.harvard.edu/oir/Research/supernova/spectra/sn06jc_comp.gif and the spectrum at .../spectra/sn2006jc-20061017.flm.gif NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2006 CBAT 2006 October 18 (CBET 676) Daniel W. E. Green