Guzik, Joyce A.2; Houdek, G.9; Chaplin, W. J.3; Kurtz, D.4; Gilliland, R. L.5; Mullally, F.6; Rowe, J. F.6; Haas, M. R.7; Bryson, S. T.7; Still, M. D.8
1 Department of Physics and Astronomy, Science and Technology, Aarhus University2 LANL3 University of Birmingham, United Kingdom4 University of Central Lancashire, United Kingdom5 STScI6 SETI Institute/NASA Ames Research Center7 NASA Ames Research Center8 NASA Ames Research Center/Bay Area Environmental Research Insitute9 Department of Physics and Astronomy, Science and Technology, Aarhus University
θ Cyg (13 Cyg) is an F4 main sequence star that, at visual magnitude V=4.48, is the brightest star observable by the Kepler spacecraft. Short-cadence photometric data using a custom aperture requiring 1800 pixels were obtained for this star during Quarter 6 (June-Sept 2010) and Quarter 8 (Jan-March 2011). We present analyses of the solar-like oscillations first discovered in the Q6 data [1, 2]. We use observational constraints from the literature and recent ground-based observations including angular diameters from optical interferometry in conjunction with the frequency data to derive stellar properties (e.g., mass, age, metallicity, extent of convection zones). We also discuss the prospects for detecting longer period gravity-mode pulsations as seen in gamma Doradus variable stars of spectral type A-F, given these constraints. With an effective temperature near 6500 K and near ‘solar’ element abundances, θ Cyg is near the red edge of the gamma Doradus instability strip, where high-order gravity-mode pulsations with periods of 1 day may be present. If the envelope convection zone of the star is not too deep, these gravity-mode pulsations may be driven by the convective blocking mechanism. The calculated envelope convection zone depth depends on the element abundance mixtures adopted for the stellar models . Asteroseismic studies of θ Cyg therefore have potential to shed light on the solar abundance problem [3, 4], as well as to put constraints on the presence and detectability of g-mode pulsations for main-sequence solar-like stars. References:  Haas, M.R. et al. 2011, BAAS, 43, No. 2, 140.07.  Guzik, J.A. et al. 2011, in Resolving the Future of Astronomy with Long Baseline Interferometry, Soccoro, NM, March 2011, ASP, in press.  Guzik, J.A. and Mussack, K. 2010, ApJ 713, 1108.  Basu, S. and Antia, H.M. 2008, Phys. Rep. 457, 217.
American Astronomical Society. Bulletin, 2012, Vol 44