Best-fit relative orbit of Achernar B around A. The measurements are shown with red dots, and the corresponding model positions as dark gray dots (linked with dashed lines). The line of nodes is represented with a gray dashed segment. The thicker part of the orbital trajectory represents the section when Achernar B is closer to us than Achernar A. The rotationally flattened profile of the photosphere of Achernar A is represented enlarged by a factor ten.