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[40.02] A Parametric Study of Cataclysmic Variable Superhump Oscillations

S. M. Baker-Branstetter (Yale University), M. A. Wood (Florida Institute of Technology)

We simulate cataclysmic variable disk superhump oscillations for systems with mass ratios q=M₂/M₁ in the range 0.03 < q < 0.30 using a three-dimensional smoothed particle hydrodynamics (SPH) code. We report the preliminary results from this parametric study in which over 4000 system orbits were calculated. In each run we start with an empty disk, build it rapidly to N=25,000 particles in 12.5 orbits, and then hold N at this value by replacing accreted particles at the L₁ point. Thus, our models most closely resemble the permanent superhumping systems. Our resulting superhump period-excess versus orbital period relation agrees well with the observations, as do the mean pulse profiles. The superhump oscillation periods do not appear to be a strong function of viscosity, although the oscillations take fewer orbits to devlop in the high viscosity disks. We find superhumps develop most rapidly in systems with q=0.075, and progressively later as the mass ratio approaches the extremes of q=0.03 and 0.30.

This work was funded by the NSF through the SARA Research Experiences for Undergraduates Summer Internship Program (NSF AST--9619939).