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The magnetic cataclysmic variable DQ Herculis was observed with the FaintObject Spectrograph onboard the Hubble Space Telescope (HST) over fourconsecutive satellite orbits, including the first observation in the UV of DQHer through eclipse minimum. Strong emission in N V, C IV, Si IV, and He II andweak emission in O I, S III, Ni II, N IV, Si III, and C III was seen. Timeresolved spectroscopy was obtained over 3 orbits with the G160L grating. At theeclipse minimum, the UV continuum was completely eclipsed for < 5% of theorbital period. This implies that the UV continuum emission region is verycompact. By contrast, none of the emission lines were completely eclipsed, mostnotably C IV which dropped by only ~75%. DQ Her is known to have intermittentpulsations in the optical and UV at a period of 71 s, due to the rotation ofthe accreting white dwarf. As in our previous observations, the UV continuumand the C IV emission show sporadic 71 s pulsations. The mechanism(s) whichdetermine the pulsation amplitudes are clearly complex. The strong emissionlines and continuum were auto-correlated during the first and third HST orbitsand all show a variability timescale of ~160 s. The intensities of these lineswere also cross-correlated with the continuum and show a strong correlationwith the continuum with a timelag of < 4 s. The data during the fourth HSTorbit were collected with the G190H grating (1600-2350 Angstroms with 1.5Angstrom spectral resolution) in standard spectroscopy mode (240 s timeresolution). These observations resolve He II 1640 into a broad (1,400 km/s),asymmetric line.Comment: 16 pages including 4 tables and 7 figures; Uses AASTeX 4.0; to appear  in The Astronomical Journal, volume 112, September 199

Time Resolved Ultraviolet Spectroscopy of DQ Herculis: Eclipses and Pulsations