000002156 001__ 2156
000002156 005__ 20160706145858.0
000002156 0247_ $$2DOI$$a10.1051/0004-6361/201322477
000002156 037__ $$aASTROimport-313
000002156 100__ $$aBeck, P. G.
000002156 245__ $$aPulsating red giant stars in eccentric binary systems discovered from Kepler space-based photometry. A sample study and the analysis of KIC 5006817
000002156 260__ $$c2014
000002156 520__ $$aContext. The unparalleled photometric data obtained by NASA's Kepler Space Telescope has led to improved understanding of red giant stars and binary stars. Seismology allows us to constrain the properties of red giants. In addition to eclipsing binaries, eccentric non-eclipsing binaries that exhibit ellipsoidal modulations have been detected with Kepler.  Aims: We aim to study the properties of eccentric binary systems containing a red giant star and to derive the parameters of the primary giant component.  Methods: We applied asteroseismic techniques to determine the masses and radii of the primary component of each system. For a selected target, light and radial velocity curve modelling techniques were applied to extract the parameters of the system and its primary component. Stellar evolution and its effects on the evolution of the binary system were studied from theoretical models. Results: The paper presents the asteroseismic analysis of 18 pulsating red giants in eccentric binary systems, for which masses and radii were constrained. The orbital periods of these systems range from 20 to 440 days. The results of our ongoing radial velocity monitoring programme with the Hermes spectrograph reveal an eccentricity range of e = 0.2 to 0.76. As a case study we present a detailed analysis of KIC 5006817, whose rich oscillation spectrum allows for detailed seismic analysis. From seismology we constrain the rotational period of the envelope to be at least 165 d, which is roughly twice the orbital period. The stellar core rotates 13 times faster than the surface. From the spectrum and radial velocities we expect that the Doppler beaming signal should have a maximum amplitude of 300 ppm in the light curve. Fixing the mass and radius to the asteroseismically determined values, we find from our binary modelling a value of the gravity darkening exponent that is significantly larger than expected. Through binary modelling, we determine the mass of the secondary component to be 0.29 ± 0.03 M?.  Conclusions: For KIC 5006817 we exclude pseudo-synchronous rotation of the red giant with the orbit. The comparison of the results from seismology and modelling of the light curve shows a possible alignment of the rotational and orbital axis at the 2s level. Red giant eccentric systems could be progenitors of cataclysmic variables and hot subdwarf B stars.
000002156 700__ $$aHambleton, K.
000002156 700__ $$aVos, J.
000002156 700__ $$aKallinger, T.
000002156 700__ $$aBloemen, S.
000002156 700__ $$aTkachenko, A.
000002156 700__ $$aGarcía, R. A.
000002156 700__ $$aØstensen, R. H.
000002156 700__ $$aAerts, C.
000002156 700__ $$aKurtz, D. W.
000002156 700__ $$aDe Ridder, J.
000002156 700__ $$aHekker, S.
000002156 700__ $$aPavlovski, K.
000002156 700__ $$aMathur, S.
000002156 700__ $$aDe Smedt, K.
000002156 700__ $$aDerekas, A.
000002156 700__ $$aCorsaro, E.
000002156 700__ $$aMosser, B.
000002156 700__ $$aVan Winckel, H.
000002156 700__ $$aHuber, D.
000002156 700__ $$aDegroote, P.
000002156 700__ $$aDavies, G. R.
000002156 700__ $$aPrša, A.
000002156 700__ $$aDebosscher, J.
000002156 700__ $$aElsworth, Y.
000002156 700__ $$aNemeth, P.
000002156 700__ $$aSiess, L.
000002156 700__ $$aSchmid, V. S.
000002156 700__ $$aPápics, P. I.
000002156 700__ $$ade Vries, B. L.
000002156 700__ $$avan Marle, A. J.
000002156 700__ $$aMarcos-Arenal, P.
000002156 700__ $$aLobel, A.
000002156 773__ $$cA36$$pAstronomy and Astrophysics$$v564$$y2014
000002156 85642 $$ahttp://esoads.eso.org/abs/2014A%26A...564A..36B
000002156 905__ $$apublished in
000002156 980__ $$aREFERD