Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-03-07
Astron.Astrophys.430:571,2005
Astronomy and Astrophysics
Astrophysics
Scientific paper
10.1051/0004-6361:20041405
We derive knowledge on the global and structural parameters of low-mass stars using asteroseismology and taking advantage of the stellar collective behavior within open clusters. We build stellar models and compute the seismic signal expected from main sequence objects in the 0.8-1.6 Msun range. We first evaluate apparent magnitudes and oscillations-induced luminosity fluctuations expected in the Hyades, the Pleiades and the alpha Persei clusters. The closest cluster presents a feasible challenge to observational asteroseismology in the present and near future. We combine seismological and classical computations to address three questions: what can be inferred about 1) mass, 2) composition and 3) extension of outer convection zones of solar analogs in the Hyades. The first issue relies on the strong sensitivity of the large separation to mass. Then large separations and second differences are used to respectively constrain metal and helium fractions in the Hyades.When plotted for several masses, the relation of effective temperature vs large separation is found to be strongly dependent on the metal content. Besides this the second difference main modulation is related to the second ionization of helium.The second difference modulations are also partly due to the discontinuity in stellar stratification at the convective envelope / radiative core transition. They permit direct insight in the stellar structure. We compute acoustic radii of the convective bases for different values of the mixing length theoryparameter alpha_MLT in convection modelling, i.e. different convective efficiency in the superadiabatic layers. For a given effectivetemperature we show that the acoustic radius changes with convection efficiency.
Ballot Jérôme
Piau Laurent
Turck-Chieze Sylvaine
No associations
LandOfFree
Seismic constraints on open clusters does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Seismic constraints on open clusters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Seismic constraints on open clusters will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-557845