  Supernovae of type Ia (SNeIa) can be produced by the explosion of
slowly-rotating carbon-oxygen white dwarfs whose mass increases beyond a
critical value by mass accretion. Collision with circumstellar material during
their photospheric and early nebular phase can enhance the bolometric
luminosity of otherwise ordinary SNeIa to become superluminous. A few
simplifying assumptions lead to a simple analytic master formula, which
describes quite well the bolometric light-curves of ordinary SNeIa and
supeluminous SNeIa in terms of few initial physical parameters. Other main
properties of SNeIa, including the empirical 'brighter-slower' Phillips'
relation that was used to standardize ordinary SNeIa as distance indicators and
led to the discovery of the accelerating expansion of the universe, are
reproduced
