A&A Supplement series, Vol. 128, March II 1998, 573-580
Received July 17; accepted September 3, 1997
and Strömgren photometry of stars in the Renson-catalogue
of Ap and Am stars
H.M. Maitzen - R. Pressberger - E. Paunzen
Send offprint request: H.M. Maitzen
Institut für Astronomie der Universität Wien,
Türkenschanzstr. 17, A-1180 Wien,
Austria
e-mail: surname@astro.ast.univie.ac.at
We have observed 131 stars of Renson's (1991) catalogue of Ap
and Am stars both in the Strömgren & Maitzen's (1976) system as a
contribution to the photometric studies of the 
broad band
flux depression feature in chemically peculiar stars. With few exceptions
the probability grouping of Renson for membership in the CP2 group of
peculiar stars is nicely reflected by peculiar values of .
Comparison with already available values yields slightly larger values
due to a minor shift in the filter g1 sampling the depression.
As found by Maitzen & Vogt (1983) the Geneva system
peculiarity parameters correlate well with . This study
demonstrates the advantageous performance of a photoelectric photometer with
a rapidly rotating filter wheel moving in a stop and go mode.
keywords: stars; chemically peculiar -- stars; early type