A Type II Supernovae Constraint on ${\nu }_e$-${\nu }_s$

The role of a resonant ${\nu }_e$-${\nu }_s$ oscillation is discussed in the event of a supernova explosion. It is concluded that a significant ${\nu }_e$-${\nu }_s$ mixing may hinder the ability of the supernova to explode. It may also cool the proto-neutron star too quickly with respect to the observed cooling time of several seconds. The constraints on the ${\nu }_e$-${\nu }_s$ mixing parameters based on the above arguments are calculated.