I produce the local astronomical society monthly newsletter and I have a nice section on comets with a visible magnitude of 12 or less (purely a plucked number).
To see what to look up in CdC, I use
http://www.aerith.net/comet/future-s.html and
http://cometchasing.skyhound.com/ which produce the correct comets at the correct time. To produce a nice chart, I use a simulated plot in CdC after downloading a fresh ephemeris data set from the MPC.
Now there is often a fairly substantial (3-5 magnitude difference) between the two magnitude sources (websites and MPC).
My question is...which one would be more accurate?
I assume the MPC download in CdC?? I hate giving the wrong info out and I have traditionally leaned towards the MPC.
And out of interest, do the MPC rely on amateur observational data or do the pros submit to it too?
Stu
MPC = Minor Planet Centre and CdC = Cartes du Ciel..but you knew that