Probing the high energies phenomena at work in early B-type stars using the RGS

Despite its relatively high abundance amongst earlytype stars, only a fewBstars have ever been observed with gratings. This resulted in our current poorunderstanding of the nature of Xray emissions from these objects. By contrast,numerous highresolution Xray spectra of Ostars provides us a case where suchgratings have significantly improved our knowledge of the physical parameters,notably by revising down the massloss rates of those objects. We thus propose aspectroscopic survey of early B type stars aimed at discovering the Xrayemission mechanisms at work in their weak winds using a range of diagnosticsonly available from highres data (line ratios, shifts, shapes, widths). truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]