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The primary component of the multiple star phi Dra is one of the brightestmagnetic chemically peculiar stars in the northern sky. Here we report resultsof a comprehensive study of the rotational photometric variability, binarity,magnetic field geometry, and surface chemical spot structure for this star. Wederived a precise photometric rotational period of 1.71650213(21) d based onone year of TESS nearly continuous space observations and discovered modulationof the stellar light curve with the phase of the 127.9-d binary orbit due tothe light time travel effect. We revised parameters of the binary orbit anddetected spectroscopic contribution of the secondary. A tomographic mappingtechnique was applied to the average intensity and circular polarisationprofiles derived from Narval high-resolution spectropolarimetric observations.This analysis yielded a detailed map of the global magnetic field topologytogether with the surface distributions of Si, Cr, and Fe abundances. Magneticmapping demonstrates that the surface field structure of phi Dra is dominatedby a distorted dipolar component with a peak field strength of 1.4 kG and alarge asymmetry between the poles. Chemical maps show an enhancement of Cr, Feand, to a lesser extent, Si in a series of spots encircling intersections ofthe magnetic and rotational equators. These chemical spot geometries do notdirectly correlate with either the local field strength or the fieldinclination.

Magnetic field topology, chemical spot distributions and photometric variability of the Ap star phi Draconis