High resolution spectroscopy of the galactic candidate LBV MWC 314 ^*

¹ Dept. of Physics & Astronomy, Univeristy of Toledo, Toledo, OH 43606–3390, U.S.A.
² Central Astronomical Observatory of the Russian Academy of Sciences at Pulkovo, Saint-Petersburg, 196140, Russia
³ Université de Mons-Hainaut, Groupe d'Astrophysique et de Spectroscopie, 20 place du Parc, B-7000 Mons, Belgium
⁴ Laboratoire d'Astronomie, Université de Montpellier 2, URA 1280 and 1981, CNRS, Place Eugène Bataillon, 34095 Monpellier Cedex 5, France
⁵ Special Astrophysical Observatory of the Russian Academy of Sciences, Karachai–Cherkess Republic, Nizhnyi Arkhyz, 357147, Russia

Send offprint request to: A.S. Miroshnichenko

Received: 5 February 1998
Accepted: 20 March 1998

Abstract

The results of high–resolution optical spectroscopy obtained for a recently suggested LBV candidate, MWC 314, are presented. Photospheric lines mostly of N ii and S ii have been found for the first time with a resolution of  Å. They imply a N/O overabundance previously reported for AG and HR Car since no O ii absorptions were detected. Nearly 400 emission lines have been identified in the spectrum between 4190 and 8864 Å many of which appear double–peaked. No significant P Cyg–type absorption components have been found for the optically thick Balmer lines. This suggests that the stellar wind of MWC 314 is non–spherical and the circumstellar envelope is viewed not edge–on. The systemic velocity measured using the emission lines of ionized metals turned out to be +55 km s^-1, which corresponds to a distance towards the object of 3.0 ± 0.2 kpc, according to the galactic rotation curve. Our analysis of the characteristics of both photospheric and wind lines resulted in an estimate of the object's T_eff of nearly 25000 K, which, however, needs further improvement. The other stellar parameters were found to be as follows: log , . Our study confirms that MWC 314 is one of the most luminous stars in the Milky Way.