1995A&A...298L...5D

We present IUE orbital phase resolved observations of the polar system RE 1938-461. We detect a strong variability of the prominent emission lines, C IV (1550 A), He II (1640 A) and N V (1240 A) at the orbital period of 140 min. Line velocity shifts are also detected with amplitudes and phasing consistent with those of the optical lines. We suggest that the bulk of the line emission arises from the magnetically confined accretion stream towards the white dwarf. Emission line flux can account for ∼3% of the soft X-ray black-body emitted at the white dwarf surface. UV continuum energy distribution indicates different components. While the far-UV can be accounted by a white dwarf at 20000K, the near-UV presents increasing flux possibly due to Balmer continuum and cyclotron emission. Continuum flux appears to vary weakly along the orbital cycle. Indications that the far-UV flux increases and steepens at superior conjunction of the white dwarf suggest a contribution of the heated polar region.