Theoretical spectra corresponding to the domain of the rotation lines of the 2-0 to 12-0 bands of the B3∑u - - X3∑g- Schumann-Runge system of O2 at 79 K are presented in graphical format. Calculated absorption cross-sections are compared with recent laboratory measurements made at the same temperature. The calculations were based on previous theoretical determinations at 300 K established after a comparison with results of laboratory measurements made at the same temperature. Such an analysis in which the band oscillator strengths are associated with averaged linewidths of the rotation lines for each band and with their underlying continuum, gives consistent values for the various spectroscopic parameters of the O2 Schumann-Runge bands.