  Since 2012, we have initiated developing systematically the simplistic to
rigorous models to prove that highly super-Chandrasekhar, as well as highly
sub-Chandrasekhar, limiting mass white dwarfs are possible to exist. We show
that the mass of highly magnetized or modified Einstein's gravity induced white
dwarfs could be significantly super-Chandrasekhar and such white dwarfs could
altogether have a different mass-limit. On the other hand, type Ia supernovae
(SNeIa), a key to unravel the evolutionary history of the universe, are
believed to be triggered in white dwarfs having mass close to the
Chandrasekhar-limit. However, observations of several peculiar, over- and
under-luminous SNeIa argue for exploding masses widely different from this
limit. We argue that explosions of super-Chandrasekhar limiting mass white
dwarfs result in over-luminous SNeIa. We arrive at this revelation, first by
considering simplistic, spherical, Newtonian white dwarfs with constant
magnetic fields. Then we relax the Newtonian assumption and consider the
varying fields, however obtain similar results. Finally, we consider a full
scale general relativistic magnetohydrodynamic description of white dwarfs
allowing their self-consistent departure from a sphere to ellipsoid.
Subsequently, we also explore the effects of modified Einstein's gravity. Our
finding questions the uniqueness of the Chandrasekhar-limit. It further argues
for a possible second standard candle, which has many far reaching
implications.
