New insights on the close circumstellar environment of Herbig Ae/Be stars

We report preliminary results of the analysis of the activity of Herbig Ae/Be stars in the FUSE spectral range. High-temperature emission lines with broad and complex profiles, often asymmetric, are present in spectra of stars with spectral type later than B9. The coolest stars of our survey also show fluorescent Fe II emission lines pumped by the H I Ly {α} line. All these lines demonstrate the presence of additional hot layers regions above the photosphere, including a chromospheric - transition region