DQ Herculis in Profile: Whole Earth Telescope Observations and Smoothed Particle Hydrodynamics Simulations

Abstract

DQ Herculis was the Summer 1997 WET northern-hemisphere primary target. The O-C phase diagram of the 71-s signal reveals out-of-eclipse phase variations resulting from the self eclipses of a nearly edge-on, non-axisymmetric disc. We work the forward problem of simulating DQ Herculis numerically using the method of smoothed particle hydrodynamics (SPH), and from the time-averaged structure calculate the O-C phase variations as a function of inclination angle. The WET and SPH O-C phase variations match to a remarkable degree, and suggest a system inclination in the range 89.5 to 89.7 degrees.