Why do Type Ia Supernovae exhibit nearly uniform peak brightness across the universe?

Answer

Because they explode upon reaching a specific mass limit (the Chandrasekhar limit).

Type Ia Supernovae result from the catastrophic explosion of a white dwarf star in a binary system when it reaches a precise mass limit, causing the resulting explosion to have a highly consistent peak luminosity across different locations.

Why do Type Ia Supernovae exhibit nearly uniform peak brightness across the universe?

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