A method for determining the beam geometry of SS 433 using high-resolution radio observations

At present, the inclination of the precession axis of the jets of SS 433 to the line of sight is not uniquely known, being either 80 or 20 deg. The corresponding angle of the jets from the precession axis is either 20 or 80 deg, respectively. It is shown that high-resolution radio observations of the knots in SS 433's jets can be used to unambiguously determine these angles along with the direction of precession (clockwise or counterclockwise) of the jets about the precession axis. On the basis of the geometry involved, the time variation of the position angle of the jets (in the plane of the sky) is calculated for each of the precession axis orientations and directions of precession. The calculated observational differences between the cases are very striking.