DETECTION OF SOLAR-LIKE OSCILLATIONS, OBSERVATIONAL CONSTRAINTS, AND STELLAR MODELS FOR theta CYG, THE BRIGHTEST STAR OBSERVED BY THE KEPLER MISSION

• Type: Article in International Scientific Journal
• Date: 2016

Authors

Guzik, JA (Author) Other; Houdek, G (Author) Other; Chaplin, WJ (Author) Other; Smalley, B (Author) Other; Kurtz, DW (Author) Other; Gilliland, RL (Author) Other; Mullally, F (Author) Other; Rowe, JF (Author) Other; Bryson, ST (Author) Other; Still, MD (Author) Other; Antoci, V (Author) Other; Appourchaux, T (Author) Other; Basu, S (Author) Other; Bedding, TR (Author) Other; Benomar, O (Author) Other; Garcia, RA (Author) Other; Huber, D (Author) Other; Kjeldsen, H (Author) Other; Latham, DW (Author) Other; Metcalfe, TS (Author) Other; Papics, PI (Author) Other; White, TR (Author) Other; Aerts, C (Author) Other; Ballot, J (Author) Other; Boyajian, TS (Author) Other; Briquet, M (Author) Other; Bruntt, H (Author) Other; Buchhave, LA (Author) Other; Campante, TL (Author) Other; Catanzaro, G (Author) Other; Christensen Dalsgaard, J (Author) Other; Davies, GR (Author) Other; Dogan, G (Author) Other; Dragomir, D (Author) Other; Doyle, AP (Author) Other; Elsworth, Y (Author) Other; Frasca, A (Author) Other; Gaulme, P (Author) Other; Gruberbauer, M (Author) Other; Handberg, R (Author) Other; Hekker, S (Author) Other; Karoff, C (Author) Other; Lehmann, H (Author) Other; Mathias, P (Author) Other; Mathur, S (Author) Other; Miglio, A (Author) Other; Molenda Zakowicz, J (Author) Other; Mosser, B (Author) Other; Murphy, SJ (Author) Other; Regulo, C (Author) Other; Ripepi, V (Author) Other; Salabert, D (Author) Other; Sousa, SG (Author) FCUP; Stello, D (Author) Other; Uytterhoeven, K (Author) Other

Journal

Title: Astrophysical Journal

Vol. 831

Final page: 17

ISSN: 0004-637X

Publisher: American Astronomical Society

Indexing

ISI Web of Knowledge - 4 Citations

Scopus - 0 Citations

Other information

Authenticus ID: P-00M-6MQ

DOI: 10.3847/0004-637x/831/1/17

Abstract (EN): theta 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 mu Hz, a large frequency separation of 83.9 +/- 0.4 mu Hz, and maximum oscillation amplitude at frequency nu(max) = 1829 +/- 54 mu Hz. 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 Re-circle dot, [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-circle dot and ages of 1.0-1.6 Gyr. theta Cyg's T-eff and log g place it cooler than the red edge of the gamma Doradus instability region established from pre-Kepler ground-based observations, but just at the red edge derived from pulsation modeling. The pulsation models show gamma Dor gravity modes driven by the convective blocking mechanism, with frequencies of 1-3 cycles per day (11 to 33 mu Hz). However, gravity modes were not seen in Kepler data; one signal at 1.776 cycles per day (20.56 mu Hz) may be attributable to a faint, possibly background, binary.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 22