Our list of candidates contains stars with 
in the
southern as well as in the northern hemisphere.
These stars must be observed spectroscopically in the blue-violet region
of the spectrum
in order to derive a classification on the MK system. Taking the main
classification
criteria for A to F-type stars (Gray & Garrison 1987,
1989a,b) into account, the following spectroscopic requirements for
our observations were chosen:
<5500
.
Bootis phenomenon. The broad hydrogen-line profiles (a
key feature of a Bootis spectrum) are
difficult to normalize properly without a good expanse of continuum on
either side of the line, and this led us to limit our highest resolution to
5500.