Cм. Byte-by-byte Description of file: gcvs_cat.dat
89- 90 A2 --- magCode The photometric system for magnitudes (G4)
Note (G4): Code for photometric system.
The main codes are p (photographic magnitudes) and V (visual,
photovisual, or Johnson's V). Several stars from the 68th Name-List
have in these positions "1." designating the 1.04 µm band of the
system introduced by G.W.Lockwood. The designations u,v,b,y refer to
the Stroemgren system. The symbols "Ic" and "Rc" mean magnitudes in
Cousins' I system. "g" designates magnitudes in the system of Thuan
and Gunn; "T" stands for broad-band Tycho magnitudes formed from B and
V measurements; "r" are red magnitudes not tied to a particular
system. An asterisk in the corresponding position means a measurement
in white light.
Второй вопрос не корректный.
