Key points are not available for this paper at this time.
All published UBV and mₚg_ mₚv_ photometry is used to determine maximum magnitudes for 31 supernovae of Type Ia (SN Ia). The main results of this work are summarized in Table I, which lists maximum magnitudes, and an estimate of their precision, for all objects which have been designated SN Ia on the basis of their spectra, and for a few supernovae in elliptical galaxies which were assumed to be of Type Ia. Figure 4 shows a Hubble diagram for SN Ia, in which the B (max) values have been corrected for absorption. With our adopted intrinsic colors this figure indicates that supernovae of Type Ia in late-type galaxies are 1. 1 +/- 0. 4 mag brighter than those in early-type galaxies. This suggests that it may be still premature to conclude that all SN Ia are good standard candles.
Bergh et al. (Fri,) studied this question.