2004IAUC.8299....2M

S. Mattila, Stockholm Observatory; W. P. S. Meikle, Imperial College, London; P. Groeningsson, Stockholm Observatory; R. Greimel and M. Schirmer, Isaac Newton Group of Telescopes; and J. A. Acosta-Pulido, Instituto de Astrofisica de Canarias, obtained infrared images and spectra of SN 2004am (IAUC 8297) on Mar. 6.9 UT, using LIRIS on the William Herschel Telescope (WHT). Preliminary reduction of the 0.89-1.53-micron spectrum shows discrete features superimposed on a significant continuum sloping slightly upwards to longer wavelengths. Emission lines of Paschen_gamma and Paschen_beta are seen, having FWZI of about 2800 km/s. It is concluded that this is a type-II supernova, but probably highly reddened within the starburst galaxy M82. The spectrum has some similarity to that of the type-IIP supernova 1995V (Fassia et al. 1998, MNRAS 299, 150) at about 85 days. A preliminary magnitude of K_s = 12 was estimated for the supernova via image-subtraction techniques, using a reference K_s-band image obtained on 2002 Jan. 3.0 with the WHT (+ INGRID) as part of the ongoing 'Nuclear Supernova Search' campaign. Adopting the unfiltered magnitude (m_u) from IAUC 8297 yields a color of m_u-K about +5. This indicates a high extinction for the supernova, as already suggested by W. Li (private comm.), corresponding to a visual extinction of about 5 magnitudes.