SIMBAD references

Convection is the first manifestation of macroscopic motions in stars. In the next decade, the extent of the external convective zone of solar-like stars will have to be derived from the eigenfrequencies of their low-degree (l=0,1 and 2) acoustic modes. In this paper, we compare different tracers of the base of the convective zone (BCZ) and show that the second difference δ₂ν stays simple and well suited for analyzing real data. We suggest the use of ∼t_BCZ=(2<Δν>)^–1-~τ_BCZ as a quasi-non-biased indicator of the BCZ acoustic radius. The method is first checked on a long-time solar observation with GOLF, then on shorter real observations by VIRGO and 10000 simulated observations of solar-like stars. We present results for different observational duration and stellar masses. The intrinsic error due to the method on the convective extent is smaller than 1.5% (in units of stellar acoustic radius) for stars with masses between 0.9 and 1.3M_☉. The limited observational interval adds a supplementary uncertainty of about 1.6% for a 150-day long simulated observation. In this study, we have also analyzed the effects of stochastic excitation and of non-continuous runs of shorter lengths. We discuss how to take into account the variations in activity.