The ultraviolet high-resolution spectrum of Feige 86.

Abstract

The high-resolution far-ultraviolet spectrum of the halo Bp star Feige 86 is studied. The energy distribution gives T(e) between 17000 and 18000 K and log g between 4 and 4.5. 1640 He II is mainly He-3. The resonance lines of NV, CIV, SiIV are present and show three components each: one shortward-shifted by about 1.5 A and one longward-shifted by about 0.4 A. The presence of these high-ionization features suggests the existence of a corona and large mass motions, posing serious problems for the diffusion theory.