| תקציר: | Empirical brighter-slower and brighter-bluer relationships satisfied by the light curves of Supernovae Type Ia allowed their use as distance indicators and led to the discovery of the accelerating expansion of the universe. I will shortly review the history of the discovery, and present a simple analytical model which yield the main properties of supernovae type Ia (SNeIa). which are produced by the thermonuclear explosion of accreting C-O white dwarfs which cross a critical mass limit. In particular, I will show that the few underlying physical assumptions of the model yield analytical expressions that reproduce quite well the observed properties of SNeIa, and in particular, their bolometric light-curves and the empirical brighter-slower and brighter-bluer relationships. |