SN 1992K - a twin to the subluminous type ia SN 1991bg

Abstract

We present spectroscopic and photometric data for SN 1992K, a Type Ia event found in the course of the Calan/Tololo supernova survey. These data show an impressive similarity with the spectra and light curves of the atypical Type Ia SN 1991bg. In particular, the remarkably red color and low luminosity of SN 1991bg are closely mimicked by SN 1992K. The discovery of SN 1992K confirms that the family of Type Ia supernovae covers a range of a factor of 5 or more in peak bolometric luminosity. Given their fast-declining light curves and considerably lower luminosity, SN 1991bg-like events are very likely selected against in traditional flux-limited supernova searches; nevertheless these objects could be quite common in a volume-limited sample.