A SEARCH FOR BE + WHITE DWARF BINARIES IN BE-RICH CLUSTERS

We propose to search for Be + white dwarf binaries in a sample of Berich youngopen clusters totaling over 100 Be stars. XMM has the capability to efficientlydetect white dwarfs accreting from the circumstellar envelopes of Be stars. Sofar no such system has been confirmed and as long as none is found the models onwhich our understanding of massive Xray binary evolution are based remainsuspect. Making the census of Be + white dwarfs binaries allows to selectbetween the different models put forward to explain the Be phenomenon. Thisprogramme is supported by an ongoing optical spectroscopic survey of theseclusters conducted by our group. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]