标题： 利用SONG-Tenerife、SONG-Australia和TESS对G8次巨星织女三的星震学研究 显示英文标题

标题： Asteroseismology of the G8 subgiant beta Aquilae with SONG-Tenerife, SONG-Australia and TESS

摘要： 我们展示了2022年和2023年使用SONG-Tenerife获得的G8亚巨星星beta Aql的时间序列径向速度，并首次使用了SONG-Australia。 我们还分析了TESS测光数据的一个重叠扇区，该数据与2022年的SONG数据重叠。 所得功率谱清楚地显示了以430微赫为中心的类似太阳的振荡。 TESS光曲线显示出较低信噪比的振荡，反映了光度测量比径向速度更容易受到粒状背景的影响的事实。 速度和光度的同时观测代表了除太阳以外任何恒星的最佳此类测量。 它们使我们能够测量总辐射光度振幅与速度振幅之比为26.6 ± 3.1 ppm/(m/s)。 我们从已发表的SOHO数据中测量了太阳的这个比值，得到19.5 ± 0.7 ppm/(m/s)，并在考虑了太阳与地球的有效温度差异后，这些值符合预期。 在太阳和beta Aql中，光度到速度的比值似乎是一个频率的函数。 我们还测量了SONG和TESS之间beta Aql振荡的相位偏移，为-113 ± 7度，这与太阳的值一致，也与一个具有类似性质的星体的三维模拟结果一致。 对于系外行星搜索来说，至关重要的是，我们认为同时的测光可以用来预测振荡对径向速度的贡献。 我们在beta Aql中测量了22个振荡模式的频率，并进行了星震学建模，得到了频率的极佳拟合。 我们得出了准确的质量和年龄值，并能够对混合长度参数施加相当强的限制。 最后，我们展示了beta Aql的振荡特性与M67疏散星团中的恒星非常相似。 显示英文摘要

摘要： We present time-series radial velocities of the G8 subgiant star beta Aql obtained in 2022 and 2023 using SONG-Tenerife and, for the first time, SONG-Australia. We also analyse a sector of TESS photometry that overlapped with the 2022 SONG data. The resulting power spectrum clearly shows solar-like oscillations centred at 430 muHz. The TESS light curve shows the oscillations at lower signal-to-noise, reflecting the fact that photometric measurements are much more affected by the granulation background than are radial velocities. The simultaneous observations in velocity and photometry represent the best such measurements for any star apart from the Sun. They allowed us to measure the ratio between the bolometric photometric amplitude and the velocity amplitude to be 26.6 +/- 3.1 ppm/(m/s). We measured this ratio for the Sun from published SOHO data to be 19.5 +/- 0.7 ppm/(m/s) and, after accounting for the difference in effective temperatures of and the Sun, these values align with expectations. In both the Sun and beta Aql, the photometry-to-velocity ratio appears to be a function of frequency. We also measured the phase shift of the oscillations in beta Aql between SONG and TESS to be -113 +/- 7 deg, which agrees with the value for the Sun and also with a 3-D simulation of a star with similar properties to beta Aql. Importantly for exoplanet searches, we argue that simultaneous photometry can be used to predict the contribution of oscillations to radial velocities. We measured frequencies for 22 oscillation modes in beta Aql and carried out asteroseismic modelling, yielding an excellent fit to the frequencies. We derived accurate values for the mass and age, and were able to place quite strong constraints on the mixing-length parameter. Finally, we show that the oscillation properties of beta Aql are very similar to stars in the open cluster M67.