Absolute Properties of the Eclipsing γ Dor Star V404 Lyrae
Abstract
We present the first highresolution spectra for the eclipsing binary V404 Lyr showing γ Dor pulsations, which we use to study its absolute properties. By fitting models to the disentangling spectrum of the primary star, we found that it has an effective temperature of T _{eff,1} = 7330 ± 150 K and a rotational velocity of v _{1} sin i = 148 ± 18 km s^{1}. The simultaneous analysis of our doublelined radial velocities and the pulsationsubtracted Kepler data gives us accurate stellar and system parameters of V404 Lyr. The masses, radii, and luminosities are M _{1} = 2.17 ± 0.06 M _{⊙}, R _{1} = 1.91 ± 0.02 R _{⊙}, and L _{1} = 9.4 ± 0.8 L _{⊙} for the primary, and M _{2} = 1.42 ± 0.04 M _{⊙}, R _{2} = 1.79 ± 0.02 R _{⊙}, and L _{2} = 2.9 ± 0.2 L _{⊙} for the secondary. The tertiary component orbiting the eclipsing pair has a mass of M _{3b } = 0.71 ± 0.15 M _{⊙} in an orbit of P _{3b } = 642 ± 3 days, e _{3b } = 0.21 ± 0.04, and a _{3b } = 509 ± 2 R _{⊙}. The third light of l _{3} = 4.1% ± 0.2% could be partly attributable to the Ktype circumbinary object. By applying a multiple frequency analysis to the eclipsesubtracted light residuals, we detected 45 frequencies with signaltonoise amplitude ratios larger than 4.0. Identified as independent pulsation modes, seven frequencies (f _{1}  f _{6}, f _{9}), their new pulsation constants, and the location in the HertzsprungRussell diagram indicate that the pulsating primary is a γ Dortype variable star.
 Publication:

The Astronomical Journal
 Pub Date:
 January 2020
 DOI:
 10.3847/15383881/ab59ce
 arXiv:
 arXiv:1910.09097
 Bibcode:
 2020AJ....159...24L
 Keywords:

 Eclipsing binary stars;
 Fundamental parameters of stars;
 Stellar oscillations;
 Spectroscopy;
 Multiperiodic pulsation;
 Asteroseismology;
 444;
 555;
 1617;
 1558;
 1078;
 73;
 Astrophysics  Solar and Stellar Astrophysics
 EPrint:
 24 pages, including 7 figures and 6 tables, accepted for publication in AJ