A (sky subtracted but uncorrected for instrument response) spectrum image showing a cross section through the coma, taken 20200713.985 with the ALPY600 (An extreme non linear gamma contrast stretch had been applied to reveal the outer regions while not saturating the inner coma) Full size image attached
Although very intense, the sodium emission is confined to a narrow region of the central coma, particularly compared with the CN band which is visible well beyond the dusty region.
Robin