ANALYSIS OF OPTICAL AND ULTRAVIOLET SPECTROSCOPY OF THE DAZ WHITE-DWARF G74-7

We present new spectroscopic and photometric observations of the cool DAZ white dwarf G74-7. These data are combined with archival HST Faint Object Spectrograph data covering the range 1700-3200 Angstrom, allow ing estimates of the Ca, Mg, and Fe abundances in this object. Our ana lysis suggests that G74-7 is a hydrogen-rich star of normal gravity, w ith T-eff = 7320 K and the following photospheric abundances: log(Ca/H )= -8.8 +/- 0.2, log(Mg/H) = -8.1 +/- 0.3, and an upper limit to log(F e/H) less than or similar to -5. These new results are considered with in the framework of current models proposed to explain the presence of heavy elements in the high-gravity photospheres of white dwarf stars.