{
  "id": "2002.10588",
  "version": "v1",
  "published": "2020-02-24T23:26:05.000Z",
  "updated": "2020-02-24T23:26:05.000Z",
  "title": "TESS Photometry of the Eclipsing $δ$ Scuti Star AI Hydrae",
  "authors": [
    "Jae Woo Lee",
    "Kyeongsoo Hong",
    "Martti H. Kristiansen"
  ],
  "comment": "16 pages, including 5 figures and 5 tables, accepted for publication in PASJ",
  "categories": [
    "astro-ph.SR"
  ],
  "abstract": "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 $f_6$).",
  "revisions": [
    {
      "version": "v1",
      "updated": "2020-02-24T23:26:05.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "scuti star ai hydrae",
      "tess photometry",
      "binary star model represents",
      "eclipse timing diagram displays",
      "independent pulsation frequencies"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 16,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}