Type II supernovae - Nonstandard candles as extragalactic distance indicators

Abstract

Type II supernova observations are used in conjunction with numerical light-curve models to derive distances. The method relies primarily on standard UBV data to fit models and observations, and treats the supernovae as individual rather than statistical events. To illustrate the technique, distances are derived for four nearby recent supernovae; in particular, for the well-observed supernova 1969l in NGC 1058 and 1970g in M101 distances of 13.7 Mpc and 7.3 Mpc, respectively, are found. These compare favorably with Sandage and Tammann's (1975) results of 14.3 Mpc and 7.2 Mpc to the groups containing the parent galaxies. The errors inherent in the method, which can be calculated, are of the order of 10%-15%; systematic errors may be larger. The most severe errors are those of reddening/extinction corrections. Eventually the method may be extended with present ground-based telescopes to estimate the Hubble constant and with the space telescope to place limits on the deceleration parameter.