2004IAUC.8286....2M

Further to IAUC 8277, M. Moore and W. Li report the LOSS discovery of a supernova, designated SN 2004W and located at R.A. = 12h43m36s.52, Decl. = +11o31'50".8 (equinox 2000.0), which is 51".6 west and 78".7 south of the nucleus of NGC 4649. Approximate KAIT magnitudes: 2003 June 4.2 UT, [20.0; 2004 Jan. 28.5, 18.8; 29.5, 18.9; Feb. 11.5, 19.3. A. V. Filippenko, R. Chornock, and R. J. Foley, University of California at Berkeley, report that inspection of CCD spectra (range 310-920 nm), obtained on Feb. 13 with the Keck I 10-m telescope (+ LRIS), shows that SN 2004W is of type Ia, specifically the underluminous SN 1991bg variety (Filippenko et al. 1992, A.J. 104, 1543; Ruiz-Lapuente et al. 1993, Nature 365, 728), roughly half a year past maximum brightness. The spectrum is dominated by very strong, broad [Ca II] 730-nm emission, with weaker iron emission lines at blue and visual wavelengths, as well as the Ca II near-infrared triplet.