J. A. Guzik, G. Houdek, W. J. Chaplin, B. Smalley, D. W. Kurtz, R. L. Gilliland, F. Mullally, J. F. Rowe, S. T. Bryson, M. D. Still, V. Antoci, T. Appourchaux, S. Basu, T. R. Bedding, O. Benomar, R. A. Garcia, D. Huber, H. Kjeldsen, D. W. Latham, T. S. MetcalfeP. I. Pápics, T. R. White, C. Aerts, J. Ballot, T. S. Boyajian, M. Briquet, H. Bruntt, L. A. Buchhave, T. L. Campante, G. Catanzaro, J. Christensen-Dalsgaard, G. R. Davies, G. Dogan, D. Dragomir, A. P. Doyle, Y. Elsworth, A. Frasca, P. Gaulme, M. Gruberbauer, R. Handberg, S. Hekker, C. Karoff, H. Lehmann, P. Mathias, S. Mathur, A. Miglio, J. Molenda-Zakowicz, B. Mosser, S. J. Murphy, C. Régulo, V. Ripepi, D. Salabert, S. G. Sousa, D. Stello, K. Uytterhoeven

Research output: Contribution to journalArticlepeer-review

7 Scopus citations


θ Cygni is an F3 spectral type magnitude V = 4.48 main-sequence star that was the brightest star observed by the original Kepler spacecraft mission. Short-cadence (58.8 s) photometric data using a custom aperture were first obtained during Quarter 6 (2010 June-September) and subsequently in Quarters 8 and 12-17. We present analyses of solar-like oscillations based on Q6 and Q8 data, identifying angular degree l = 0, 1, and 2 modes with frequencies of 1000-2700 μHz, a large frequency separation of 83.9 ± 0.4 μHz, and maximum oscillation amplitude at frequency ν max = 1829 ± 54 μHz. We also present analyses of new ground-based spectroscopic observations, which, combined with interferometric angular diameter measurements, give T eff = 6697 ± 78 K, radius 1.49 ± 0.03 R o, [Fe/H] = -0.02 ± 0.06 dex, and log g = 4.23 ± 0.03. We calculate stellar models matching these constraints using the Yale Rotating Evolution Code and the Asteroseismic Modeling Portal. The best-fit models have masses of 1.35-1.39 M o and ages of 1.0-1.6 Gyr. θ Cyg's T eff and log g place it cooler than the red edge of the γ Doradus instability region established from pre-Kepler ground-based observations, but just at the red edge derived from pulsation modeling. The pulsation models show γ Dor gravity modes driven by the convective blocking mechanism, with frequencies of 1-3 cycles per day (11 to 33 μHz). However, gravity modes were not seen in Kepler data; one signal at 1.776 cycles per day (20.56 μHz) may be attributable to a faint, possibly background, binary.

Original languageEnglish (US)
Article number17
JournalAstrophysical Journal
Issue number1
StatePublished - Nov 1 2016

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

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