Direct analysis of spectra of the Type Ic supernova SN1994I

Synthetic spectra generated with the parameterized supernova synthetic-spec trum code SYNOW are compared to observed photospheric-phase spectra of the Type Ic supernova SN 1994I. The observed optical spectra can be well matche d by synthetic spectra that are based on the assumption of spherical symmet ry. We consider the identification of the infrared absorption feature obser ved near 10250 Angstrom which previously has been attributed to He I lambda 10830 and regarded as strong evidence that SN 1994I ejected some helium. W e have difficulty accounting for the infrared absorption with He I alone. I t could be a blend of He I and C I lines. Alternatively, we find that it ca n be fitted by Si I lines without compromising the fit in the optical regio n. In synthetic spectra that match the observed spectra, from 4 days before to 26 days after the time of maximum brightness, the adopted velocity at t he photosphere decreases from 17,500 to 7000 km s(-1). Simple estimates of the kinetic energy carried by the ejected mass give values that are near th e canonical supernova energy of 10(51) ergs. The velocities and kinetic ene rgies that we find for SN 1994I in this way are much lower than those that we find elsewhere for the peculiar Type Ic SNe 1997ef and 1998bw, which the refore appear to have been hyperenergetic.