AI Hya has been known as an eclipsing binary with a monoperiodic $\delta$ Sct pulsator. We present the results from its {\it TESS} photometry observed during Sector 7. Including our five minimum epochs, the eclipse timing diagram displays the apsidal motion with a rate of $\dot{\omega}$ = 0.075$\pm$0.031 deg year$^{-1}$, which corresponds to an apsidal period of U = 4800$\pm$2000 years. The binary star model represents that the smaller, less massive primary component is 427 K hotter than the pulsating secondary, and our distance of 612$\pm$36 pc is in good agreement with the $Gaia$ distance of 644$\pm$26 pc. We subtracted the binary effects from the observed {\it TESS} data and applied a multifrequency analysis to these residuals. The result reveals that AI Hya is multiperiodic in its pulsation. Of 14 signals detected, four ($f_1$, $f_2$, $f_3$, $f_6$) may be considered independent pulsation frequencies. The period ratios of $P_{\rm pul}/P_{\rm orb}$ = 0.012$-$0.021 and the pulsation constants of $Q$ = 0.30$-$0.52 days correspond to $\delta$ Sct pulsations in binaries. We found that the secondary component of AI Hya pulsates in both radial fundamental $F$ modes ($f_2$ and $f_3$) and non-radial $g_1$ modes with a low degree of $\ell$ = 2 ($f_1$ and $f_6$).

中文翻译：

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日食 δ Scuti 星 AI Hydrae 的 TESS 光度测量

AI Hya 被称为具有单周期 $\delta$ Sct 脉动器的食双星。我们展示了在第 7 扇区观察到的 {\it TESS} 测光结果。包括我们的五个最小时期，日食时序图显示了以 $\dot{\omega}$ = 0.075$\pm$0.031 deg 的速率的近点运动年$^{-1}$，对应于 U = 4800$\pm$2000 年的顶点周期。双星模型表示更小、质量较小的初级组件比脉动次级组件热 427 K，我们 612$\pm$36 pc 的距离与 $Gaia$ 距离 644$\pm$26 pc 非常吻合。我们从观察到的 {\it TESS} 数据中减去二元效应，并对这些残差应用多频分析。结果表明，AI Hya 的脉动是多周期的。在检测到的 14 个信号中，有四个（$f_1$、$f_2$、$f_3$、$f_6$) 可以被认为是独立的脉动频率。$P_{\rm pul}/P_{\rm orb}$ = 0.012$-$0.021 的周期比和 $Q$ = 0.30$-$0.52 天的脉动常数对应于双星中的 $\delta$ Sct 脉动。我们发现 AI Hya 的次要分量在径向基本 $F$ 模式（$f_2$ 和 $f_3$）和非径向 $g_1$ 模式中脉动，具有低度数 $\ell$ = 2（$f_1$和 $f_6$）。