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

S. Bernabei, V. Ripepi, A. Ruoppo, M. Marconi, M. J. P. F. G. Monteiro, E. Rodriguez, T. D. Oswalt, S. Leccia, F. Palla, G. Catanzaro, P. J. Amado, M. J. Lopez-Gonzalez, F. J. Aceituno

Abstract
Context. The study of pulsation in Pre–Main–Sequence intermediate-mass stars represents an important tool for deriving information on fundamental stellar parameters and internal structure, as well as for testing current theoretical models. Interest in this class of variable stars has significantly increased during the last decade and about 30 members are presently known in the literature.
Aims. We have constructed the frequency spectrum of the oscillations in V346 Ori. We apply asteroseismic tools to these data to estimate the intrinsic parameters (mass, luminosity, effective temperature) of V346 Ori and to obtain information on its internal structure.
Methods. CCD time series photometry in the Johnson V filter has been obtained for a total of 145.7 h of observations distributed over 36 nights. The resulting light curves have been subjected to a detailed frequency analysis using updated numerical techniques. Photometric and spectroscopic data have also been acquired to determine reliable estimates of the stellar properties.
Results. We have identified 13 oscillation frequencies, 6 of which with higher significance. These have been compared with the predictions of non-radial adiabatic models. The resulting best fit model has a mass of 2.1±0.2 M_⊙, luminosity log L/L_⊙ = 1.37 (−0.13, +0.11), 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.

Keywords
stars: pre-main sequence – stars: oscillations – stars: individual V346 Orionis – stars: fundamental parameters

Notes
Based on data collected with the REM 0.6-m, Loiano 1.5-m, SARA 0.9-m and SNO 1.5-m telescopes

Astronomy and Astrophysics
Volume 501, Page 279
July 2009

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