SIMBAD references

We consider the presence of absorption lines due to accreted metals in the photosphere of the magnetic (28 MG) white dwarf in the prototype polar AM Herculis. We have applied the Massa-Fitzpatrick flux-calibration correction to the archival IUE NEWSIPS SWP spectra of AM Her obtained during the optical low states, when the accretion rate is very low and emission due to thermal bremsstrahlung and cyclotron processes is essentially absent. We have examined low-state spectra at UV maximum (phase∼0.6: main accreting pole most directly exposed to the observer) and UV minimum (phase∼0.1: line of sight perpendicular to the magnetic field). We have used the model atmosphere codes TLUSTY, SYNSPEC, and ROTIN to determine the surface temperature of the white dwarf at each UV phase during quiescence and the chemical abundance of detected metal species. We find that the abundances of metals in the photosphere of the accreting magnetic degenerate in AM Her range between 0.05 and 0.001 times solar. To our knowledge, these are the first photospheric metal abundances to be determined for any accreting magnetic white dwarf in a magnetic cataclysmic variable. Our preliminary results indicate that (1) there is no correlation between the time since the last high state and either the surface temperature or the chemical abundance and (2) the metal abundances do not appear to be significantly different between spectra obtained at UV maximum and UV minimum. This implies that, based upon the limited sample of spectra presented here, the abundance of metals may be similar across the stellar surface. This would result if sideways diffusion and spreading of material from the small polar-cap accretion regions had occurred.