1 Introduction

In this paper we present the results of a photometric survey for Be stars within and around six young clusters in the Magellanic Clouds. Such studies have been carried out on Galactic clusters but they are limited there by the relative paucity of Be stars. The young populous Magellanic Cloud clusters examined in this paper present us with large samples of Be stars in a range of metallicity environments and the opportunity to further examine the mechanism for formation of Be stars.

Searches for Be stars in the Magellanic Clouds have been made by Feast (1972) using objective prism techniques, and the more recently by Grebel et al. (1992), Bessell & Wood (1992) (who gave a brief description of some of the results presented in this paper) and Grebel (1997) using CCD-based imaging photometry. These latter searches involved imaging through an H$\alpha$ filter so that Be stars, which show strong H$\alpha$ emission, stand out in comparison to normal stars. Photometric techniques such as these are very efficient methods of identifying Be stars, in particular within dense clusters where spectroscopy is difficult.

The main purpose of the present study is to provide a sample of Be stars for follow-up spectroscopy and to see if there are differences in Be star populations between different clusters and between clusters and the local field population. The results of the follow-up spectroscopy will be presented in a subsequent paper. Because the present study is ground-based, its spatial resolution is seeing limited, which means that we are unable to search for Be stars in the cluster cores. In another paper, we will present the results of a search for Be stars in the cluster cores using HST imaging. The present paper provides the comparison sample of Be stars in the local field and the outer cluster zones. The complete data set of ground-based and HST images will allow an accurate comparison of field and cluster Be stars properties. In this paper, however, we make some initial comparisons with the more limited data set described herein.