Bibcode
Guzik, J. A.; Houdek, G.; Chaplin, W. J.; Smalley, B.; Kurtz, D. W.; Gilliland, R. L.; Mullally, F.; Rowe, J. F.; Bryson, S. T.; Still, M. D.; Antoci, V.; Appourchaux, T.; Basu, S.; Bedding, T. R.; Benomar, O.; Garcia, R. A.; Huber, D.; Kjeldsen, H.; Latham, D. W.; Metcalfe, T. S.; Pápics, P. I.; White, T. R.; Aerts, C.; Ballot, J.; Boyajian, T. S.; Briquet, M.; Bruntt, H.; Buchhave, L. A.; Campante, T. L.; Catanzaro, G.; Christensen-Dalsgaard, J.; Davies, G. R.; Doğan, G.; Dragomir, D.; Doyle, A. P.; Elsworth, Y.; Frasca, A.; Gaulme, P.; Gruberbauer, M.; Handberg, R.; Hekker, S.; Karoff, C.; Lehmann, H.; Mathias, P.; Mathur, S.; Miglio, A.; Molenda-Żakowicz, J.; Mosser, B.; Murphy, S. J.; Régulo, C.; Ripepi, V.; Salabert, D.; Sousa, S. G.; Stello, D.; Uytterhoeven, K.
Referencia bibliográfica
The Astrophysical Journal, Volume 831, Issue 1, article id. 17, 22 pp. (2016).
Fecha de publicación:
11
2016
Revista
Número de citas
16
Número de citas referidas
15
Descripción
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 ⊙, [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 ⊙ 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.