BE STARS IN OPEN CLUSTERS .1. UVBY-BETA PHOTOMETRY

We present uvby beta photometry for Be stars in eight open clusters an d two OB associations. It is shown that Be stars occupy anomalous posi tions in the photometric diagrams, which can be explained in terms of the circumstellar continuum radiation contribution to the photometric indices. In the (b - y)(0) - M(V) plane Be stars appear redder than th e non emission B stars, due to the additional reddening caused by the hydrogen free-bound and free-free recombination in the circumstellar e nvelope. In the c(0)- M(V) plane the earlier Be stars present lower c( 0) values than absorption-line B stars, which is caused by emission in the Balmer discontinuity, while the later Be stars deviate towards hi gher co values, indicating absorption in the Balmer discontinuity of c ircumstellar origin.