KIC 10417986: Spectroscopic confirmation of the nature of the binary system with a δ Scuti component

Abstract

KIC 10417986 is a short orbital period (0.0737 d) ellipsoidal variable star with a δ Scuti and γ Doradus hybrid pulsations component discovered by Kepler. The ground-based spectroscopic observations were carried out in the winters of 2020 and 2021 to investigate the binary nature of this star. We derive the orbital parameters using the rvfit code with a result of K1 = 29.7 $\pm$ 1.5 km/s, γ = -18.7 $\pm$ 1.7 km/s, and confirm an orbital period of 0.84495 d instead of the result given by Kepler. The atmospheric parameters of the primary are determined by the synthetic spectra fitting technique with the estimated values of Teff = 7411 $\pm$ 187 K, log g = 4.2 $\pm$ 0.3 dex, [M/H] = 0.08 $\pm$ 0.09 dex and vsini = 52 $\pm$ 11 km/s. KIC 10417986 is a circular orbit binary system. From the single-lined nature and mass function of the star, the derived orbital inclination is 26 $\pm$ 6°, and the mass of the secondary is from 0.43 to 0.7 M_sun, which should be a late-K to early-M type star. Fourteen frequencies are extracted from Kepler light curves, of which six independent frequencies in the high-frequency region are identified as the p-mode pulsations of δ Scuti star, and one independent frequency in the low-frequency region (f2 = 1.3033 c/d) is probably the rotational frequency due to the starspots rather than the ellipsoidal effect or g-mode of γ Doradus.

18 pages, 8 figures

References in corpus (13)

• Determining stellar atmospheric parameters and chemical abundances of FGK stars with iSpec
• Modern stellar spectroscopy caveats
• Main-Sequence Effective Temperatures from a Revised Mass-Luminosity Relation Based on Accurate Properties
• Tidal dissipation in binary systems
• A unifying explanation of complex frequency spectra of gamma Dor, SPB and Be stars: combination frequencies and highly non-sinusoidal light curves
• Tidal Synchronization and Differential Rotation of Kepler Eclipsing Binaries
• New planetary and EB candidates from Campaigns 1-6 of the K2 mission
• The role of turbulent pressure as a coherent pulsational driving mechanism: the case of the delta Scuti star HD 187547
• Recurrent starspot activity and differential rotation in KIC 11560447
• KIC 10736223: An Algol-type eclipsing binary just undergone the rapid mass-transfer stage
• Delta Scuti Variables
• Exploring the convective core of the hybrid $\delta$ Scuti-$\gamma$ Doradus star CoRoT 100866999 with asteroseismology
• Pulsations of the SX Phe Star BL Camelopardalis