The surface chemistry of the magnetic Ap star HD 147010

The magnetic field model is a low-order multipole expansion based on the variations of the line of sight and surface magnetic fields with rotation. Spectral synthesis was carried out using zeeman, a program which takes into account the influence of the magnetic field. A simple model of uniform abundance in each of two rings in the observed magnetic hemisphere with equal spans in colatitude was used. The new magnetic field measurements enabled us to re-analyse the rotation period of HD 147010, finding P = 3.9207 +/- 0.0003 d. The line of sight and surface magnetic field strengths vary from about -2000 to -5000 G and 11000 to 17000 G, respectively. Our analysis finds large overabundances of Fe-peak and rare-earth elements relative to the solar ratios. In all cases, where strong variability in surface chemistry is observed, abundances are higher near the magnetic equator as compared to the magnetic pole. HD 147010 appears to be an Ap star that is highly rich in rare-earth elements that are of the order of 10(5) times more abundant than in the Sun. This analysis adds to the growing number of hot Ap stars for which both the magnetic field and abundance distribution have been studied in detail.