Time history of the observed IQ metrics for the period shown in Fig. 7 before the start of the nominal mission, from 1 October 2023 (mission day 92) until 26 November 2023 (mission day 148). (a) Variation of the average Gaia colour B_pR_p per 12 h bin. (b) Variation of the ellipticity component e₁. (c) Variation of the ellipticity component e₂. To underscore the correlation with baseplate temperature, −e₂ is displayed. (d) Variation of R². The dashed red lines indicate baseplate temperature T_BP (THM05) with arbitrary scaling for reference.