Top and middle: Butterfly diagrams of the radial (top) and azimuthal (middle) large-scale magnetic field of ι Hor. These synoptic maps display the longitudinally averaged magnetic field strength (color bar, in gauss), extracted over 10° latitudinal strips on the individual ZDI epochs (Figs. 1 to 3). Bottom: Best two-period fit to the Ca II H&K S-index variations obtained by Amazo-Gómez et al. (2023). The shaded region encapsulates the 1σ period and amplitude uncertainties. Day “0” corresponds to BJD = 2457300.78580 (2015-10-05 06:51:33.12 UTC), and a secondary x-axis indicates the number of stellar rotations covered by the campaign (assuming P_rot = 7.73 d).