  We discuss the possibility of reconstructing the newly formed proto-neutron
star radius from the late time neutrino signal. A black-body emission is
assumed for the neutron star cooling phase. We parametrize the neutrino
time-integrated fluxes based on simulations of Roberts and Reddy. A likelihood
analysis of the inverse-beta decay and elastic scattering events in
Hyper-Kamiokande is performed in both three flavor and an effective one flavor
scenario. We show that the precision achievable in the radius reconstruction
strongly depends on a correlation with the pinching parameter and therefore the
corresponding prior. Although this correlation hinders the precise measurement
of the newly formed neutron star radius, it could help measure the pinching
parameters with good accuracy in view of the current constraints on neutron
star radius, or if the neutron star radius is precisely measured.
