Phase function of the combined, inactive 288P system. The data points are from PSF-fitting of two point sources to individual exposures for visit 24 (α ~ 3°), and from fitting minimum-stacked pairs as described in Sect. 3.1 for visits 13–23. The scatter of the data reflects the rotation-induced variability of the system’s brightness. The solid line shows the best-fit H− G phase function with H_V = (16.99 ± 0.03) and G = (0.10 ± 0.04). The shaded area reflects the 1σ uncertainty of the fit, and the dashed lines indicate the interval ΔV_red = ±0.25 covered by the rotational lightcurve.