Multi-site photometry of the pulsating Herbig Ae star V346 Ori

Abstract

Context. The study of pulsation in pre-main-sequence intermediate-mass stars represents an important tool for deriving information about fundamental stellar parameters and internal structure, as well as testing theoretical models. Interest in this class of variable stars has increased significantly during the last decade and about 30 members are presently known in the literature.Aims. After constructing the frequency spectrum of oscillations in V346 Ori, we apply asteroseismic tools to these data to estimate the intrinsic parameters (mass, luminosity, effective temperature) of V346 Ori and obtain information about its internal structure.Methods. CCD time-series photometry in the Johnson V filter was obtained for a total of 145.7 h of observations distributed over 36 nights. The resulting light curves were subjected to a detailed frequency analysis using updated numerical techniques. Photometric and spectroscopic data were also acquired to determine reliable estimates of the stellar properties.Results. We identified 13 oscillation frequencies, 6 of which with higher significance. These were compared with the predictions of non-radial adiabatic models. The resulting best-fit model corresponds to a mass of 2.1 ± 0.2 M, luminosity L/L = 1.37+0.11-0.13, and effective temperature 7300 ± 200 K. These values are marginally consistent with the association of V346 Ori to Orion OB1a. Alternatively, V346 Ori could be placed at a slightly larger distance than previously estimated. © 2009 ESO.