  Two main physical mechanisms are used to explain supernova explosions:
thermonuclear explosion of a white dwarf(Type Ia) and core collapse of a
massive star (Type II and Type Ib/Ic). Type Ia supernovae serve as distance
indicators that led to the discovery of the accelerating expansion of the
Universe. The exact nature of their progenitor systems however remain unclear.
Radio emission from the interaction between the explosion shock front and its
surrounding CSM or ISM provides an important probe into the progenitor star's
last evolutionary stage. No radio emission has yet been detected from Type Ia
supernovae by current telescopes. The SKA will hopefully detect radio emission
from Type Ia supernovae due to its much better sensitivity and resolution.
There is a 'supernovae rate problem' for the core collapse supernovae because
the optically dim ones are missed due to being intrinsically faint and/or due
to dust obscuration. A number of dust-enshrouded optically hidden supernovae
should be discovered via SKA1-MID/survey, especially for those located in the
innermost regions of their host galaxies. Meanwhile, the detection of
intrinsically dim SNe will also benefit from SKA1. The detection rate will
provide unique information about the current star formation rate and the
initial mass function. A supernova explosion triggers a shock wave which expels
and heats the surrounding CSM and ISM, and forms a supernova remnant (SNR). It
is expected that more SNRs will be discovered by the SKA. This may decrease the
discrepancy between the expected and observed numbers of SNRs. Several SNRs
have been confirmed to accelerate protons, the main component of cosmic rays,
to very high energy by their shocks. This brings us hope of solving the
Galactic cosmic ray origin's puzzle by combining the low frequency (SKA) and
very high frequency (Cherenkov Telescope Array: CTA) bands' observations of
SNRs.
