A STUDY OF THE ATMOSPHERE OF THE METALLIC-LINE STAR 15 VUL

We performed new observations of the metallic-line star 15 Vul with th e echelle spectrograph of the 1-m telescope of the Special Astrophysic al Observatory. Based on measurements of the equivalent widths for mor e than 600 green and yellow-red lines of 24 elements, we redetermined the atmospheric chemical composition of this star. We discuss the resu lts of our iron-abundance determination in the atmosphere of 15 Vul fr om Fe I and Fe II lines and analyze the effect of choosing lines and o f the oscillator strengths used on the determination of log epsilon (F e). Using Stenflo-Lindegren's multiline technique, we diagnose a magne tic field at the surface of 15 Vul with a complex structure. The field strength was found from 164 Fe I lines in the wavelength range 4300 t o 6700 Angstrom to be fH = 2390 +/- 540 G. An analysis of Fe I lines w ith various excitation potentials chi(c) provides evidence that the ma gnetic regions on the surface of 15 Vul are cooler than the surroundin g quiet photosphere.