Page "Chandrasekhar limit" Paragraph 29

A strong indication of the reliability of Chandrasekhar's formula is that the absolute magnitudes of supernovae of Type Ia are all approximately the same ; at maximum luminosity, M < sub > V </ sub > is approximately-19. 3, with a standard deviation of no more than 0. 3 .< sup >, ( 1 )</ sup > A 1-sigma interval therefore represents a factor of less than 2 in luminosity.

This seems to indicate that all type Ia supernovae convert approximately the same amount of mass to energy.