From the recent work of the Evolution and Seismic Tools Activity (ESTA, Monteiro et al. 2006; Lebreton et al. 2008), whose Task 2 is devoted to compare pulsational frequencies computed using most of the pulsational codes available in the asteroseismic community, the dependence of the theoretical frequencies with non-physical choices is now quite well fixed. To ensure that the accuracy of the computed frequencies is of the same order of magnitude or better than the observational errors, some requirements in the equilibrium models and the numerical resolutions of the pulsational equations must be followed. In particular, we have verified the numerical accuracy obtained with the Saclay seismic model, which is used to study the solar g-mode region (60 to 140$μ$Hz). We have compared the results coming from the Aarhus adiabatic pulsation code (ADIPLS), with the frequencies computed with the Granada Code (GraCo) taking into account several possible choices. We have concluded that the present equilibrium models and the use of the Richardson extrapolation ensure an accuracy of the order of $0.01 μHz$ in the determination of the frequencies, which is quite enough for our purposes.
A comparison between observed Algol-type double stars in the Solar neighborhood and evolutionary computations of galactic case A binaries with a B-type primary at birth
Fundamental properties of solar-like oscillating stars from frequencies of minimum $Δν$ : II. Model computations for different chemical compositions and mass
类太阳恒星的振荡频率之间的巨大间隔是恒星平均密度的度量。在观测到的频率范围内,分离被认为是基本恒定的。然而,详细的研究表明,它们不是恒定的,它们的变化也不是随机的,而是对我们理解恒星结构和演化具有很强的诊断潜力。在这方面,最小大间隔的频率是非常有用的工具。从这些频率,除了大的分离和最大振幅的频率,Yıldız等人最近开发了新的方法来找到几乎所有的基本恒星属性。在本研究中,我们的目标是从频率中找到金属丰度和氦丰度,并将Yıldız等人给出的关系推广到更宽的恒星质量范围和任意金属丰度($Z$)和氦丰度($Y$)。我们发现,金属丰度的影响是{显着}的基本参数。例如,对于恒星质量,表达式必须乘以$(Z/Z_{\sun})^{0.12}$。对于任意氦丰度,$ M \propto (Y/Y_{\sun})^{0.25} $。从纯星震量确定$Z$和$Y$的方法是根据振荡频率间隔中振荡分量的振幅(\Dnu最大值和最小值之间的差异)。此外,我们证明了第一个最大值和第二个最小值之间的差异是非常敏感的$Z$。它还取决于$ν_{\rm min1}/ν_{\rm max}$和频率之间的小间隔。这种依赖性使我们开发了一种从振荡频率中找到$Z$(和$Y$)的方法。估计值和模型$Z$值之间的最大差异约为14%,而$Y$值为10%。
A High-Precision Numerical Framework for Time-Varying Solar Neutrino Flux with Full Earth Matter Oscillation Corrections for Global Underground Laboratories