Type 1a Supernovae Mass Range

Type 1a supernovae are results of exploding white dwarfs. These 1a supernovae have fairly uniformed luminosity making them the focus of many studies for determining  the expansion and size of the universe. Scientists observe that when the white dwarf reaches the Chandraskhar limit, 1.44 solar masses, it collapses into a 1a supernovae. Scientists thought that having this uniformed mass limit is what causes the uniformed luminosity however it is shown that 1a supernovae actually have a wider range of masses. Some 1a supernovae fall short of the Chandraskhar limit and others even exceed the limit; however all these still fit the normal Typne 1a supernovae. There must be something more going on that creates this uniformed luminosity of the Type 1a supernovae.

http://phys.org/news/2014-03-standard-ia-supernovae-surprisingly-large.html