Detection of HIP 99770 b on 31 May 2023. The circular panel indicates the field of view of the GRAVITY science fibre. The map within visualises the $\mathrm{\Delta }{\chi }_{\mathrm{r}\mathrm{e}\mathrm{d}}^2$ over a two-dimensional grid of positions relative to the host star, which is located at the origin of the axes, and thus, outside the field of view. Each $\mathrm{\Delta }{\chi }_{\mathrm{r}\mathrm{e}\mathrm{d}}^2$ value is the difference between how well a model with and without a coherent point source of light at a given position (ΔRA, ΔDec) describes the interferometric observables. Thus, the strongest peak within the field of view corresponds to the position of the companion, while the secondary peaks (the so-called side lobes) are typical for interferometric observations and mostly depend on the u-v plane coverage.