2003IAUC.8144....2L

D. C. Leonard, University of Massachusetts, Amherst; and R. Chornock and A. V. Filippenko, University of California, Berkeley, report that inspection of CCD spectra (range 300-930 nm) of the type-II SN 2003ed (IAUC 8129), obtained on May 25 UT with the Keck- I telescope, show it to bear a striking resemblance to the spectrum of the type-IIb SN 1993J, about 32 days past explosion (Matheson et al. 2000, A.J. 120, 1487). In addition to features typically seen in type-II supernovae at this stage, lines of He I with P-Cyg profiles have emerged, suggesting that the progenitor of SN 2003ed lost a substantial fraction of its hydrogen envelope prior to exploding. In addition, spectropolarimetry (range 570-940 nm) shows an average continuum polarization of about 1 percent, with strong modulations across the H_alpha and Ca II-infrared-triplet features of up to about 1 percent in the individual Stokes parameters. While some of the continuum polarization may be due to interstellar dust, the changes across the line features suggest substantial polarization due to scattering by aspherical supernova ejecta, as has been inferred for SN 1993J at a similar epoch (Tran et al. 1997, PASP 109, 489).