English

TIC 322208686: An Eclipsing System with $\gamma$ Doradus Pulsations and a Third Component on a Wider Orbit

Solar and Stellar Astrophysics 2025-11-25 v1

Abstract

TIC 322208686 is known to be a detached binary that exhibits two types of variability: pulsation and eclipse. We present the physical properties of the target star using the short-cadence TESS data from sectors 24, 57, and 58, and our echelle spectra that show the presence of a tertiary companion. The spectral analysis led to the triple-lined radial velocities and the atmospheric parameters of the eclipsing components. Joint modeling of these observations reveals that the eclipsing pair contains two F-type stars with masses 1.564±0.0121.564\pm0.012 MM_\odot and 1.483±0.0121.483\pm0.012 MM_\odot, radii 1.588±0.0111.588\pm0.011 RR_\odot and 1.500±0.0121.500\pm0.012 RR_\odot, effective temperatures 7028±1007028\pm100 K and 7020±1107020\pm110 K, and luminosities 5.51±0.325.51\pm0.32 LL_\odot and 4.90±0.324.90\pm0.32 LL_\odot. The light contributions of the three stars obtained from this modeling match well with those calculated from the observed spectra. The binary star parameters are in satisfactory agreement with evolutionary model predictions for age tt = 0.4 Gyr and metallicity ZZ = 0.03. We extracted 11 significant frequencies from the TESS light residuals with the binary effects removed. Of these, five signals between 0.65 day1^{-1} and 1.89 day1^{-1} can be considered as γ\gamma Dor pulsations originating mainly from the primary component, while the other frequencies are likely instrumental artifacts or combination terms. These results suggest that TIC 322208686 is a hierarchical triple, containing a pulsating eclipsing pair and a tertiary companion.

Keywords

Cite

@article{arxiv.2511.17819,
  title  = {TIC 322208686: An Eclipsing System with $\gamma$ Doradus Pulsations and a Third Component on a Wider Orbit},
  author = {Jae Woo Lee and Kyeongsoo Hong and Min-Ji Jeong and Jang-Ho Park and Pakakaew Rittipruk and Hye-Young Kim},
  journal= {arXiv preprint arXiv:2511.17819},
  year   = {2025}
}

Comments

23 pages, including 9 figures and 5 tables, accepted for publication in AJ