Intensity measured at − 0.8 km s⁻¹ on saturated HO spectra obtained on 24 September 2015 between 7.5 and 24 h UT while scanning across the nucleus (see the spectrum examples in Fig. 2). The blue and red dots show the value before and after gain correction, respectively. The jumps before correction correspond to times when MIRO pointed on the nucleus. Error bars are only plotted for the uncorrected data.