EAS Publications Series

Stellar Evolution and Seismic Tools for Asteroseismology - Diffusive Processes in Stars and Seismic Analysis
C.W. Straka, Y. Lebreton and M.J.P.F.G. Monteiro (eds)
EAS Publications Series, 26 (2007) 187-194
DOI: 10.1051/eas:2007137

Current Status of ESTA-Task2

A. Moya

Instituto de Astrofísica de Andalucía (CSIC), CP3004, Granada, Spain

(Published online: 20 June 2007)

Abstract
A report on the current status of the ESTA- Task 2 (oscillation frequencies comparison) is presented. Several types of comparisons have been made using the frequencies provided by different numerical codes. The equilibrium model is the same for all of them, and additionally some requirements such as boundary conditions, no re-meshing, etc, are also imposed. Some unexpected differences appear in the frequency and large separation comparisons. In the high frequency region these differences can be due to the order of the integration scheme used to solve the partial differential equations (or to the lack of number of mesh points in the outer layers). In the region around the fundamental radial mode and the low frequency region, important differences appear for the avoided crossing and the trapped modes respectively, the reason maybe due to the different sensitivity of each code to the profile of the Brunt-Väisälä frequency. The next step will be to test the accuracy of the codes using a model with a larger number of mesh points and with a better described Brunt-Väisälä frequency.