I.U.E. high resolution observations of hot stars emitting coronal x-rays

The far UV resonance lines of a sample of 21 early-type stars, which were observed in the soft X-Ray band with the $\text{Einstein}$ satellite, are examined using I.U.E. high resolution spectra to search for possible correlation between the X-Ray coronal emission and far UV spectral properties. In particular, those quantities that can give information on the structure of the outer envelope (such as wind terminal velocities, emission-absorption ratios) are measured and compared with the observed X-Ray flux.