球状星团M22中变星的均一化星表：成员资格、物理参数与距离
A Homogenized Catalogue of Variable Stars in the Globular Cluster M22: Membership, Physical Parameters, and Distance
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中文总结 AI 辅助
本文通过多源时域测光构建M22变星均一化星表，识别94颗成员变星，并利用RR Lyrae和SX Phe星推导金属丰度与距离，证实多星族特征。
中文摘要 AI 辅助
我们利用文献以及OGLE和Gaia-DR3数据中的时域测光，对球状星团M22（NGC 6656）天区内的变星进行了测光分析。在天区的666颗变星样本中，我们识别出94颗为星团成员，其中包括10颗RRab型、17颗RRc型、2颗II型造父变星、15颗SX Phe型、15颗SR型变星和22颗食双星。这些成员中有14颗未被收录在《球状星团变星星表》中。通过对RR Lyrae光变曲线进行傅里叶分解，我们推导出[Fe/H] = -1.73 ± 0.17 dex，距离d = 3.27 ± 0.14 kpc。在RRc型星中，V15显示出额外的频率，其频率比f_0.61/f_1O = 0.6152，与RR_0.61现象一致。利用成员SX Phe星的周光关系，我们得到d = 3.31 ± 0.17 kpc，与RR Lyrae距离一致。我们构建了仅包含星团成员的颜色-星等图（CMD），从而确认了星团中RR Lyrae星的演化状态。所有拟合的等时线均不能令人满意地重现CMD形态，这与M22中存在多个恒星族群的结论一致。
英文摘要
We present a photometric analysis of the variable stars in the field of the globular cluster M22 (NGC 6656), using time-series photometry from the literature and from OGLE and Gaia-DR3 data. From a sample of 666 variable stars in the field, we identify 94 as cluster members, including 10 RRab, 17 RRc, 2 Type II Cepheids, 15 SX Phe, 15 SR stars and 22 eclipsing binaries. Fourteen of these members are not included in the Catalogue of Variable Stars in Globular Clusters. Through the Fourier decomposition of the RR Lyrae light curves, we derived $[\mathrm{Fe/H}] = -1.73 \pm 0.17$ dex and $d = 3.27 \pm 0.14$ kpc. Among the RRc stars, V15 shows an additional frequency with a frequency ratio $f_{0.61}/f_\mathrm{1O} = 0.6152$, consistent with the RR$_{0.61}$ phenomenon. Using P-L relations for member SX Phe stars, we obtained $d = 3.31 \pm 0.17$ kpc, consistent with the RR Lyrae distance. We constructed a CMD comprising only cluster members, which allows us to confirm the evolutionary status of the cluster's RR Lyrae stars. None of the fitted isochrones satisfactorily reproduces the CMD morphology, which is consistent with the presence of multiple stellar populations in M22.
