Figure 1:
Spectra of comet C/2001 Q4 at 3.7 AU (top) and 0.98 AU
showing part of the R branch of the CN (0, 0) band.
The corresponding quantum numbers are indicated at the top.
The major differences are related to the heliocentric distance and show up in
the excitation of lines of higher quantum number when closer to the Sun.
The intensity scale is relative only.