skip to main content

DOE PAGESDOE PAGES

Title: Detection of Solar-Like Oscillations, Observational Constraints, and Stellar Models for θ Cyg, the Brightest Star Observed by the Kepler Mission

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 justmore » at the red edge derived from pulsation modeling. Lastly, 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.« less
Authors:
ORCiD logo [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [7] ;  [7] ;  [8] ;  [2] ;  [9] ;  [10] ;  [11] ;  [12] ;  [13] ;  [11] ;  [2] ;  [14] ;  [15] more »;  [16] ;  [17] ;  [18] ;  [19] ;  [10] ;  [20] ;  [21] ;  [22] ;  [3] ;  [23] ;  [2] ;  [24] ;  [25] ;  [26] ;  [27] ;  [3] ;  [23] ;  [28] ;  [29] ;  [2] ;  [30] ;  [2] ;  [31] ;  [32] ;  [15] ;  [3] ;  [33] ;  [34] ;  [11] ;  [35] ;  [36] ;  [13] ;  [37] ;  [11] ;  [35] « less
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  2. Aarhus Univ. (Denmark)
  3. Aarhus Univ. (Denmark); Univ. of Birmingham (United Kingdom)
  4. Keele Univ. (United Kingdom)
  5. Univ. of Central Lancashire, Preston (United Kingdom)
  6. Pennsylvania State Univ., University Park, PA (United States)
  7. NASA Ames Research Center (ARC), Moffett Field, Mountain View, CA (United States)
  8. NASA Ames Research Center (ARC), Moffett Field, Mountain View, CA (United States); Bay Area Environmental Research Inst., Sonoma, CA (United States)
  9. Univ. Paris-Sud, Orsay (France)
  10. Yale Univ., New Haven, CT (United States)
  11. Aarhus Univ. (Denmark); Univ. of Sydney, NSW (Australia)
  12. Univ. of Sydney, NSW (Australia); New York Univ., Abu Dhabi (United Arab Emirates)
  13. Univ. of Paris Diderot, Gif-sur-Yvette (France)
  14. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
  15. Space Science Inst., Boulder, CO (United States)
  16. Katholieke Univ., Leuven (Belgium)
  17. Aarhus Univ. (Denmark); Univ. of Sydney, NSW (Australia); Australian Astronomical Observatory, North Ryde, NSW (Australia)
  18. Katholieke Univ., Leuven (Belgium); Radboud Univ., Nijmegen (Netherlands)
  19. Univerisite de Toulouse, Tarbes, France
  20. Univ. de Liege (Belgium)
  21. Aarhus Univ. (Denmark); Aarhus Katedralskole, Skolegyde, Aarhus (Denmark)
  22. Univ. of Copenhagen (Denmark). The Niels Bohr Inst.; Univ. of Copenhagen (Denmark). Centre for Star and Planet Formation and Natural History Museum of Denmark
  23. Astrophysical Observatory of Catania (Italy)
  24. Aarhus Univ. (Denmark); Univ. of Birmingham (United Kingdom); Univ. of Paris Diderot, Gif-sur-Yvette (France)
  25. Aarhus Univ. (Denmark); National Center for Atmospheric Research, Boulder, CO (United States)
  26. Univ. of Chicago, IL (United States)
  27. Keele Univ. (United Kingdom); Univ. of Warwick, Coventry (United Kingdom)
  28. Apache Point Observatory, Sunspot, NM (United States); New Mexico State Univ., Las Cruces, NM (United States)
  29. Saint Mary's Univ., Halifax, NS (Canada)
  30. Aarhus Univ. (Denmark); Max Planck Inst. for Solar System Research, Gottingen (Germany)
  31. Thuringer Landessternwarte Tautenburg (Germany)
  32. Univ. de Toulouse, Tarbes (France); National Centre for Scientific Research (CNRS), Tarbes (France). Center for Spatial Study of Radiation
  33. Univ. of Wroclaw (Poland)
  34. Sorbonne Univ., Paris (France). LESIA Observatoire de Paris
  35. Inst. of Astrophysics of the Canary Islands, Tenerife (Spain); Univ. de La Laguna, Tenerife (Spain)
  36. Istituto Nazionale di Fisica Nucleare (INFN), Napoli (Italy). Osservatorio Astronomico di Capodimonte
  37. Univ. of Porto (Portugal)
Publication Date:
Report Number(s):
LA-UR-16-22306
Journal ID: ISSN 1538-4357; TRN: US1701349
Grant/Contract Number:
AC52-06NA25396; KEPLER08-0013; 12-ATP12-0130; NNX12AE17G; 269194; 267864; DNRF106; NNX13AE70G; NNX16AI09G; AST-1105930; AST-1514676; AYA2010-17803
Type:
Accepted Manuscript
Journal Name:
The Astrophysical Journal (Online)
Additional Journal Information:
Journal Name: The Astrophysical Journal (Online); Journal Volume: 831; Journal Issue: 1; Journal ID: ISSN 1538-4357
Publisher:
Institute of Physics (IOP)
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
National Aeronautic and Space Administration (NASA); USDOE
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS
OSTI Identifier:
1345147