Relative astrometry of the µ Her A subsystem. The plot is centred on the primary µ Her Aa. Data points are colour-coded by epoch, progressing from purple to yellow. To illustrate the constraints provided by relative astrometry alone, we display 600 random draws from the corresponding posterior distribution (red traces). The solid black lines trace the orbit derived from our full joint fit, with the median solution highlighted in white. The bottom panels show residuals versus time in separation, ρ, and position angle, θ.