The astroseismic behaviour of very-metal-poor stars (–3 < [Fe/H] < –2) is not well constrained due to the lack of suitable observations, and typically knowledge of their fundamental properties (such as age, or mass) is scaled from the Sun, using global oscillation parameters. Testing such scaling relations is important, not least because inconsistencies in and corrections to the scaling relationships have been identified even for near-Solar metallicity stars. Daniel Huber and colleagues report on a spectroscopic survey of a small number of metal-poor stars in the Kepler oscillating red giant sample, and identify a very-metal-poor star in the Galactic halo with [Fe/H] = −2.66. Modelling the star in some detail yields an age of 12.0 ± 1.0 Gyr, with excellent agreement between different models.

The star, KIC 814490, is a low-luminosity red giant, which makes frequency modelling challenging due to the inherently low oscillation amplitudes. Remarkably, however, high signal-to-noise oscillations were identified in the Kepler observations, and when modelled with six stellar structure and atmosphere models (BeSPP, BASTA and four prescriptions of MESA), disagreements on stellar age and mass were found to be at the 2–3% level.

由于缺乏合适的观测，并且通常缺乏对其基本属性（例如年龄或质量）的了解，非常贫金属恒星 (–3 < [Fe/H] < –2) 的天震行为没有得到很好的限制使用全局振荡参数从太阳缩放。测试这种标度关系很重要，尤其是因为即使对于近太阳金属丰度恒星，也已经发现了标度关系的不一致和修正。 Daniel Huber 及其同事报告了对开普勒振荡红巨星样本中少量贫金属恒星的光谱调查，并在银河晕中识别出一颗[Fe/H] = -2.66 的贫金属恒星。对恒星进行一些细节建模得到了 12.0 ± 1.0 Gyr 的年龄，不同模型之间具有极好的一致性。

这颗恒星 KIC 814490 是一颗低光度红巨星，由于固有的低振荡幅度，使得频率建模具有挑战性。然而，值得注意的是，开普勒观测中发现了高信噪比振荡，并且当用六个恒星结构和大气模型（BeSPP、BASTA 和 MESA 的四个处方）进行建模时，发现恒星年龄和质量方面的分歧非常大。 2-3% 的水平。