Top panel: solar RV as derived by observing different reflecting bodies vs. the time in JD on the lower axis and in years on the top axis, respectively. The errors are derived in Sect. 4.2. The red dots indicate measurements that are affected by the rotation of the reflecting body or by other systematics and that are excluded from further analysis. Middle panel: chromospheric Ca II K index corresponding to our RV measurements vs. the time (see Sect. 2.2). The red dots indicate the excluded data points as in the top panel, while the errors are derived in Sect. 2.3. Lower panel: same as the middle panel, but for the total mean magnetic flux introduced in Sect. 2.2 and whose errors are derived in Sect. 2.3.