When trying to use w/ 'add' 'add_labels' etc. All other
messier and the herschel 400 NGC's go through fine:
pp3: Warning: Invalid M index: 40.
Logged In: YES
PP3 bases on the NGC catalogue. Therefore, all IC and
Messier objects that are not available in the NGC don't work.
M24 is a pseudo-cluster only in Messier and IC, M 40 is a
double star (i.e. not a nebula at all), and M 45 is also not
in the NGC (like the Coma cluster or the Hyades).