Type I supernova 1974g in NGC 4414

The paper analyzes six image-tube spectrograms of supernova 1974g in NGC 4414, which were obtained at post-maximum phases of +14 and +40 days over the wavelength range from 4500 to 7000 A with a dispersion of 150 A/mm and a resolution of about 5 A. All features normally seen in this wavelength region in Type I supernova spectra are observed in the spectrum of SN 1974g, and the time of maximum light is estimated to be approximately JD 2442172. The photographic image-tube spectra are converted to relative flux units, an absolute-flux calibration is performed, and the absolute energy distribution of the supernova is determined for the two indicated phases. A broad emission feature at 6480 A is tentatively attributed to H-alpha, the distance to NGC 4414 is estimated as approximately 15 Mpc, and absolute B magnitude of -19.0 is computed for the supernova along with a photospheric radius of the order of 10 to the 15th power cm and a total observed luminous energy of about 10 to the 51st power erg. These values are shown to be consistent with previous estimates for Type I supernovae.