Oscillations in the PMS delta Scuti star V346 Ori

F. J. G. Pinheiro, D. F. M. Folha, M. Marconi, V. Ripepi, F. Palla, M. J. P. F. G. Monteiro, S. Bernabei

Resumo
We report the discovery of periodicities in the light curve of the Pre-Main Sequence (PMS) Herbig Ae star V346 Ori. We interpret variations in the light curve of the star as the superposition of at least two periodic signals that result from delta Scuti-type stellar oscillations. The computation of linear non-adiabatic radial pulsation models for PMS stars reproduces these periods for a 1.55 M_sun star with T_eff = 7410 K and log L/L_sun = 0.74 pulsating in the fundamental and in the second overtone. If our assumption of radial oscillations is indeed correct, the star's location on the HR diagram places it at a distance significantly smaller than that of the Orion star forming region, hence raising questions regarding the evolutionary status of V346 Ori. Observations with better time sampling and spanning a longer period of time are needed if the latter question is to be addressed fully. Tables 1 and 2 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/399/271

Astronomy and Astrophysics
Volume 399, Página 271
fevereiro 2003

DOI: 10.1051/0004-6361:20021792