Best fitted limb to the CHEOPS chord (in blue) and ellipses within their respective 1-σ region. Two solutions can be obtained, one with the centre north of the chord (in red), and another to the south (in black). The black line stands for the preferred resulted central position of Quaoar (f₀,  g₀) considering the centre to the south of the chord. The red line is the unlikely northern solution. The solution in black is the preferred solution as it agrees more with the expected orbit of Quaoar based on the NIMA ephemeris and its uncertainty (yellow dashed region). The green dashed line corresponds to the negative observation used to eliminate some of the solutions that cross it (light grey ellipses).