The absolute luminosity

The measurement of the intrinsic luminosity ${ \cal M}_{filtre}$ defined by equation 2.18 rests on a precise estimate of the distance from the supernova using indicators of secondary distance (in general of the stars céphéides contained in the galaxy host). This type of measurement is rather difficult because the methods are intrinsically rather vague. Moreover, the distance must be sufficiently small to allow the observation of the céphéides. Consequently, there is only one ten supernovæ which one could measure the distance.

Two types of measurement are made, the first considers only the magnitude observed, the second corrects it using the law of Phillips which allow as we will see it in the continuation `` to standardize '' the luminosity of the supernovæ to the maximum. The results in the filters B and V of jha1999, saha2001 and gibson2001 converge towards the same values:

$${\cal M}_B(max) = -19.5 \pm 0.1$$ (5.1)

$${\cal M}_V(max) = -19.5 \pm 0.1$$ (5.2)

and

$${\cal M}_B^{corr}(max) = -19.3 \pm 0.1$$ (5.3)

$${\cal M}_V^{corr}(max) = -19.3 \pm 0.1$$ (5.4)

The typical energy rejected in luminous form reached $10^{11 } \rm \, L_\odot$, or the same luminosity as an average galaxy.