  Proton-neutron quasi-particle random phase approximation (pn-QRPA) theory has
recently being used for calculation of stellar weak interaction rates of
$fp$-shell nuclide with success. Neutrino losses from proto-neutron stars play
a pivotal role to decide if these stars would be crushed into black holes or
explode as supernovae. The product of abundance and positron capture rates on
$^{55}$Co is substantial and as such can play a role in fine tuning of input
parameters of simulation codes specially in the presupernova evolution.
Recently we introduced our calculation of capture rates on $^{55}$Co, in a
luxurious model space of $7 \hbar \omega$, employing the pn-QRPA theory with a
separable interaction. Simulators, however, may require these rates on a fine
scale. Here we present for the first time an expanded calculation of the
neutrino energy loss rates and positron capture rates on $^{55}$Co on an
extensive temperature-density scale. These type of scale is appropriate for
interpolation purposes and of greater utility for simulation codes. The pn-QRPA
calculated neutrino energy loss rates are enhanced roughly up to two orders of
magnitude compared with the large-scale shell model calculations and favor a
lower entropy for the core of massive stars.
