Issue |
A&A
Volume 423, Number 3, September I 2004
|
|
---|---|---|
Page(s) | 1051 - 1061 | |
Section | Stellar structure and evolution | |
DOI | https://doi.org/10.1051/0004-6361:20035898 | |
Published online | 12 August 2004 |
Seismic extraction of the convective extent in solar-like stars*
The observational point of view
Service d'Astrophysique, CEA/DSM/DAPNIA, CE Saclay, 91191 Gif-sur-Yvette Cedex, France e-mail: [jballot;cturck;rgarcia]@cea.fr
Received:
18
December
2003
Accepted:
29
April
2004
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 ( 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
stays simple and well suited
for analyzing real data.
We suggest the use of
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
10 000 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
(in units of stellar acoustic radius)
for stars with masses between 0.9 and 1.3
.
The limited observational interval adds
a supplementary uncertainty of about
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.
Key words: convection / stars: oscillations / stars: interiors / Sun: helioseismology / methods: data analysis
© ESO, 2004
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.