Model for atomic oxygen visible line emissions in Comet C/1995 O1 Hale-Bopp

► Model for green, red-doublet emission of atomic oxygen in high production rate comet. ► Green line emission is largely produced by photodissociation of CO2 and H2O. ► Higher width of green line is due to multiple production sources of O(1S) atom. ► Photon degradation is different in high water production rate comets. ► Model calculated 6300 Å line emission is consistent with ground based observations.