CoRoT 102918586: a Gamma Dor pulsator in a short period eccentric eclipsing binary

Abstract

Pulsating stars in eclipsing binary systems are powerful tools to test stellar models. Binarity enables to constrain the pulsating component physical parameters, whose knowledge drastically improves the input physics for asteroseismic studies. The study of stellar oscillations allows us, in its turn, to improve our understanding of stellar interiors and evolution. The space mission CoRoT discovered several promising objects suitable for these studies, which have been photometrically observed with unprecedented accuracy, but needed spectroscopic follow-up. A promising target was the relatively bright eclipsing system CoRoT 102918586, which turned out to be a double-lined spectroscopic binary and showed, as well, clear evidence of Gamma Dor type pulsations. We obtained phase resolved high-resolution spectroscopy with the Sandiford spectrograph at the McDonald 2.1m telescope and the FEROS spectrograph at the ESO 2.2m telescope. Spectroscopy yielded both the radial velocity curves and, after spectra disentangling, the component effective temperatures, metallicity and line-of-sight projected rotational velocities. The CoRoT light curve was analyzed with an iterative procedure, devised to disentangle eclipses from pulsations. We obtained an accurate determination of the system parameters, and by comparison with evolutionary models strict constraints on the system age. Finally, the residuals obtained after subtraction of the best fitting eclipsing binary model were analyzed to determine the pulsator properties. We achieved a quite complete and consistent description of the system. The primary star pulsates with typical γ Dor frequencies and shows a splitting in period which is consistent with high order g-mode pulsations in a star of the corresponding physical parameters. The value of the splitting, in particular, is consistent with pulsations in l = 1 modes.

12 pages, 10 figures. Accepted for publication in Astronomy and Astrophysics

References in corpus (10)

• The Geneva-Copenhagen Survey of the Solar neighbourhood II. New uvby calibrations and rediscussion of stellar ages, the G dwarf problem, age-metallicity diagram, and heating mechanisms of the disk
• CLES, Code Liegeois d'Evolution Stellaire
• A heuristic derivation of the uncertainty of the frequency determination in time series data
• A spectroscopic study of southern (candidate) gamma Doradus stars. II. Detailed abundance analysis and fundamental parameters
• Absolute dimensions of eclipsing binaries. XXVI. Setting a new standard: Masses, radii, and abundances for the F-type systems AD Bootis, VZ Hydrae, and WZ Ophiuchi
• Spectrum Analysis of Bright Kepler Gamma Doradus Candidate Stars
• Chemical evolution of high-mass stars in close binaries. I. The eclipsing binary V453 Cygni
• Multi-object spectroscopy of stars in the CoRoT fields I: Early-type stars in the CoRoT-fields IRa01, LRa01, LRa02
• Planetary transit candidates in the CoRoT LRa01 field
• MOST discovers a multimode delta Scuti star in a triple system: HD 61199

Cited by in corpus (23)

• Probing the interior physics of stars through asteroseismology
• Eclipsing Binary Stars as Benchmarks for Trigonometric Parallaxes in the Gaia Era
• Physical parameters and the projection factor of the classical Cepheid in the binary system OGLE-LMC-CEP-0227
• Detection of a large sample of Gamma Dor stars from Kepler space photometry and high-resolution ground-based spectroscopy
• KIC 3858884: a hybrid δ Sct pulsator in a highly eccentric eclipsing binary
• Bayesian mass and age estimates for transiting exoplanet host stars
• Wavelets: a powerful tool for studying rotation, activity, and pulsation in Kepler and CoRoT stellar light curves
• KIC 10080943: An eccentric binary system containing two pressure- and gravity-mode hybrid pulsators
• KIC 11285625: a double-lined spectroscopic binary with a gamma Dor pulsator discovered from Kepler space photometry
• The Age and Interior Rotation of Stars from Asteroseismology
• Kepler Eclipsing Binaries with $\delta$ Scuti/$\gamma$ Doradus Pulsating Components 1: KIC 9851944
• New pulsating stars detected in EA-type eclipsing binary systems based on TESS data
• The Eclipsing System V404 Lyr: Light-Travel Times and Gamma Doradus Pulsations
• HD 183648: a Kepler eclipsing binary with anomalous ellipsoidal variations and a pulsating component
• HIDES spectroscopy of bright detached eclipsing binaries from the $Kepler$ field - III. Spectral analysis, updated parameters, and new systems
• Tango of celestial dancers: A sample of detached eclipsing binary systems containing g-mode pulsating components. A case study of KIC9850387
• Asteroseismology of binary stars and a compilation of core overshoot and rotational frequency values of OB stars
• Asteroseismology of Eclipsing Binary Stars in the Kepler Era
• The classification of frequencies in the γ Doradus / δ Scuti hybrid star HD 49434
• V2653 Ophiuchii with a pulsating component and Ppuls-Porb, Ppuls-g correlations for gamma-Dor type pulsators
• Multiple star systems observed with CoRoT and Kepler (invited review)
• KIC 10417986: Spectroscopic confirmation of the nature of the binary system with a δ Scuti component
• OO Dra: an Algol-type binary formed through an extremely helium-poor mass accretion revealed by asteroseismology