OBSERVATIONS OF RAPID BLUE VARIABLES .11. DO HERCULIS

A study has been made of the phase, amplitude and shape of the 71-s periodic light variations around several binary cycles of DQ Her. It is shown that, relative to the usually adopted period of 71-06550s, there is a 360° phase shift through eclipse. The light curve is sinusoidal within observational error. The observed phase variations are difficult to explain except in terms of a grazing eclipse of a white dwarf pulsating in a non-radial quadrupole mode. © 1972 Oxford University Press. All rights reserved.