The Line Variability of 78 Vir (A2p SrCrEu) in the Far-ultraviolet

Line variations are studied in the far-ultraviolet spectra of 78 Vir collected with International Ultraviolet Explorer at phases of far-UV maximum and at phases of far-UV minimum . The far-UV spectrum of 78 Vir is populated with low-excitation transitions of light elements and iron-peak elements. The low excitation C  i and N  i lines are stronger at phases of far-UV minimum . Carbon appears to be underabundant and aluminum very underabundant in the atmosphere of 78 Vir. The lines of Si  i and Si  ii are stronger at phases of far-UV minimum . Many lines which strengthen at phases of far-UV minimum are due to low-excitation lines of Fe  ii and Cr  ii which suggests that both iron and chromium are unevenly distributed over the surface of 78 Vir.