A new method to determine the total reaction cross section sigma (R) from e
lastic scattering angular distributions based on the generalized optical th
eorem for charged particles is presented. Angular distributions from explor
atory measurements performed in the C-12 + C-12 system at energies found in
stellar hydrostatic carbon burning (E-c.m. = 2.5MeV-1.6MeV) show the appli
cability of the theorem.