Tango of celestial dancers: A sample of detached eclipsing binary systems containingg-mode pulsating components

Abstract

Context.Eclipsing binary systems with components that pulsate in gravity modes (gmodes) allow for simultaneous and independent constraints of the chemical mixing profiles of stars. The high precision of the dynamical masses and radii as well as the imposition of identical initial chemical compositions and equivalent ages provide strong constraints during the modelling ofg-mode period-spacing patterns.Aims.We aim to assemble a sample ofg-mode pulsators in detached eclipsing binaries with the purpose of finding good candidates for future evolutionary and asteroseismic modelling. In addition, we present a case study of the eclipsing binary KIC9850387, identified as our most promising candidate, and detail the results of the observational spectroscopic, photometric, and asteroseismic analysis of the system.Methods.We selected all of the detached eclipsing binaries in theKeplereclipsing binary catalogue withKeplerInput Catalogue (KIC) temperatures between 6000 K and 10 000 K, and performed a visual inspection to determine the presence and density ofgmodes, and the presence ofg-mode period-spacing patterns in their frequency spectra. We then characterised our sample based on theirg-mode pulsational parameters and binary and atmospheric parameters. A spectroscopic follow-up of our most promising candidate was then performed, and the orbital elements of the system were extracted. We then performed spectral disentangling followed by atmospheric modelling and abundance analysis for the primary star. We utilised an iterative approach to simultaneously optimise the pulsational and eclipse models, and subsequently performed an analysis of the pressure- (p-) andg-mode pulsational frequencies.Results.We compiled a sample of 93Keplereclipsing binary stars withg-mode pulsating components and identified clearg-mode period-spacing patterns in the frequency spectra of seven of these systems. We also identified 11 systems that contained hybridp- andg-mode pulsators. We found that theg-mode pulsational parameters and the binary and atmospheric parameters of our sample are weakly correlated at best, as expected for detached main-sequence binaries. We find that the eclipsing binary KIC9850387 is a double-lined spectroscopic binary in a near-circular orbit with a hybridp- andg-mode pulsating primary withMp= 1.66−0.01+0.01M⊙andRp= 2.154−0.004+0.002R⊙, and a solar-like secondary withMs= 1.062−0.005+0.003M⊙andRs= 1.081−0.002+0.003R⊙. We findℓ = 1 andℓ = 2 period-spacing patterns in the frequency spectrum of KIC9850387 spanning more than ten radial orders each, which will allow for stringent constraints of stellar structure during future asteroseismic modelling.