In the A-F star region we have at present three different surveys,
carried out on photographic plate material, obtained with slit spectrographs and
classified in the traditional way in the MK system. These are
a) Cowley et al. (1969). The survey covers the
B8-F0 stars, in the northern sky down to 6.5 and -10 declination. This
survey shall be abbreviated CJ.
b) Garrison & Gray (Gray & Garrison 1987, 1989a, 1989b and
Garrison & Gray 1994). The survey covers most B8-F2 stars, in
both hemispheres at least up to 5.0 It shall be abbreviated as GG.
c) Abt & Morell (1995) The survey covers most of the northern
B8-F1 star, down to 6.5 and -20 declination. It shall be abbreviated as
AbM.
We have provided just the rough limits of each survey, but for the strict definition of each program the reader should consult the original papers. It is clear from the preceding summary that a large superposition between the three surveys exists. The surveys have been carried out with different dispersions, namely 125 (CJ), 67 (GG) and 40 (AbM) A/mm. All observers used the framework of the MK system and their classifications should thus have a high degree of homogeneity and of intercomparability.