Short-period variations in the moving line spectrum of SS 433

Abstract

Evidence is presented for the existence of short-period variations in the wavelengths of the moving lines of SS 433. Attention is given the possibility that the effects result from the temporal sampling of the data, and it is determined that this is not the case. In order to encompass the light time effects for arbitrary orientation and location of the emitting regions' velocity vectors, consistent with the assumption that they are stationary and antiparallel in a rotating frame, the geometrical representation is generalized. It is concluded, from the best fit to the residuals in the data compared to this assumption, that the velocity vectors vary in a 6.06-day period, but the 'blue' and 'red' beams remain nearly parallel throughout this variation.