TESS对7颗新发现的高振幅δ Scuti（δ型盾牌座）星的观测
TESS Observations of Seven Newly Identified High-amplitude $δ$ Scuti Stars
- Xinjiang Astronomical Observatory, Chinese Academy of Sciences（中国科学院新疆天文台）
- School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）
- Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick（华威大学物理系聚变、太空与天体物理中心）
- Institute of Geophysics, University of Tehran（德黑兰大学地球物理学研究所）
- Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台光学天文重点实验室）
- Ministry of Education Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi’an Jiaotong University（西安交通大学物理学院教育部非平衡合成与调控凝聚态物质重点实验室）
- Ulugh Beg Astronomical Institute, Uzbekistan Academy of Sciences（乌兹别克斯坦科学院乌鲁格别克天文研究所）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
该研究通过TESS观测发现7颗新的高振幅δ Scuti星，分析其脉动模式、与RR Lyrae星的区分难点及金属丰度与周期的关系，指出需更大样本光谱观测以获更准确结论。
AI中文摘要：
我们报告了7颗新发现的高振幅δ Scuti（HADS）星。其中2颗星（TIC 30977864和TIC 387379145）呈现纯径向脉动，无径向外模式激发；TIC 30977864被归类为双模式HADS星，其余4颗星可能表现出三模式HADS行为。TIC 112682462和TIC 255603395的光变曲线、周光图位置及周期比图均与RR Lyrae星极为相似，但若无光谱观测，难以确定这两颗星是HADS还是RR Lyrae星。TIC 281695001的基频振幅小于第一谐频，表明存在值得进一步分析的有趣现象。我们利用Netzel & Smolec提供的数据分析了金属丰度与周期的关系：176颗星的金属丰度分布范围较宽，从-2.0 dex到0.5 dex，周期跨度为0.05至0.20天，这种金属丰度的随机分布可能导致P₁/P₀比值的离散性。为得出更准确的结论，未来对更大样本的HADS星进行光谱观测至关重要，这些观测将提供精确的自转速度和更准确的金属丰度测定。
英文摘要：
We report seven newly identified high-amplitude $δ$ Scuti (HADS) stars. Among them, two stars (TIC 30977864 and TIC 387379145) exhibit pure radial pulsation without the excitation of non-radial modes. TIC 30977864 is classified as a double-mode HADS star, while the other four stars potentially show triple-mode HADS behavior. TIC 112682462 and TIC 255603395 closely resemble RR Lyrae stars based on their light curves, position in the period-luminosity diagram, and the period-ratio diagram. However, without spectral observations, it is challenging to ascertain whether these two stars are HADS or RR Lyrae stars. TIC 281695001 exhibits a fundamental frequency amplitude smaller than that of the first overtone, suggesting the presence of intriguing phenomena that necessitate further analysis. We analyzed the relationship between metallicity and period using data provided by Netzel & Smolec. The metallicities of the 176 stars display a broad distribution ranging from -2.0 dex to 0.5 dex, with periods spanning 0.05 to 0.20 days. This random distribution of metallicities may contribute to the dispersion observed in the $P_1/P_0$ ratio. To derive more accurate conclusions, future spectroscopic observations of a larger sample of HADS stars are crucial. These observations will provide precise rotational velocities and more accurate determinations of metallicities.
