THE STELLAR EXTREME-ULTRAVIOLET RADIATION-FIELD

The local extreme ultraviolet (EUV) radiation held from stellar source s has been determined by combining the EUV spectra of 54 stars, taken with the spectrometers aboard the Extreme Ultraviolet Explorer satelli te. The resultant spectrum over the range 70-730 Angstrom is estimated to be 95% complete above 400 Angstrom and 90% complete above 200 Angs trom. The flux contributed by two B stars and three hot white dwarfs d ominate the spectrum except at the shortest wavelengths, where an asso rtment of EUV source types contribute. The high electron densities mea sured toward nearby stars can be accounted for by photoionization from this radiation held, but the spectrum is too soft to explain the over ionization of helium with respect to hydrogen recently measure in the Local Cloud.