Solar-like Oscillations in KIC 11395018 and KIC 11234888 from 8 Months of Kepler Data

Savita Mathur (1) , Rasmus Handberg (2) , Tiago L. Campante (3) , Rafael A. Garcia (4) , Thierry Appourchaux (5) , Timothy R. Bedding (6) , Benoît Mosser (7, 8) , William J. Chaplin (9) , Jérôme Ballot (10) , Othman Benomar (5) , Alfio Bonanno (11) , Enrico Corsaro (11) , Patrick Gaulme (5) , Saskia Hekker (9) , Clara Regulo (12) , David Salabert (12) , Graham A. Verner (13) , Timothy R. White (6) , I. M. Brandão (14) , Orlagh L. Creevey (12) , Gülnur Dogan (2) , Yvonne P. Elsworth (9) , Daniel Huber (6) , S. J. Hale (9) , Günter Houdek (15) , Christoffer Karoff (2) , Travis S. Metcalfe (1) , Joanna Molenda-Zakowicz (16) , M. J. P. F. G. Monteiro (3) , Michael J. Thompson (1) , Jörgen Christensen-Dalsgaard (2) , Ronald L. Gilliland (17) , Steven D. Kawaler (18) , Hans Kjeldsen (2) , E. V. Quintana (19) , Dwight T. Sanderfer (19) , S. E. Seader (19)

1 High Altitude Observatory, National Center for Atmospheric Research
2 DASC - Danish AsteroSeismology Centre
3 Universidade do Porto = University of Porto
4 CEA - Commissariat à l'énergie atomique et aux énergies alternatives
5 IAS - Institut d'astrophysique spatiale
6 SIfA - Sydney Institute for Astronomy
7 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique
8 Pôle Planétologie du LESIA
9 School of Physics and Astronomy, University of Birmingham
10 IRAP - Institut de recherche en astrophysique et planétologie
11 INAF-OACt - INAF-Osservatorio Astrofisico di Catania
12 ULL - Universidad de La Laguna [Tenerife - SP]
13 School of Mathematical Sciences, Queen Mary Unversity of London
14 Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto
15 IfA - Institut für Astronomie, Universität Wien
16 Astronomical Institute, University of Wroclaw
17 STScI - Space Telescope Science Institute
18 Department of Physics and Astronomy, Iowa State University
19 SETI Institute, NASA Ames Research Center, Moffett Field

We analyze the photometric short-cadence data obtained with the Kepler mission during the first 8 months of observations of two solar-type stars of spectral types G and F: KIC 11395018 and KIC 11234888, respectively, the latter having a lower signal-to-noise ratio (S/N) compared with the former. We estimate global parameters of the acoustic (p) modes such as the average large and small frequency separations, the frequency of the maximum of the p-mode envelope, and the average line width of the acoustic modes. We were able to identify and to measure 22 p-mode frequencies for the first star and 16 for the second one even though the S/N of these stars are rather low. We also derive some information about the stellar rotation periods from the analyses of the low-frequency parts of the power spectral densities. A model-independent estimation of the mean density, mass, and radius is obtained using the scaling laws. We emphasize the importance of continued observations for the stars with low S/N for an improved characterization of the oscillation modes. Our results offer a preview of what will be possible for many stars with the long data sets obtained during the remainder of the mission.

Domaines: Astrophysique [astro-ph]

Savita Mathur, Rasmus Handberg, Tiago L. Campante, Rafael A. Garcia, Thierry Appourchaux, et al.. Solar-like Oscillations in KIC 11395018 and KIC 11234888 from 8 Months of Kepler Data. The Astrophysical Journal, 2011, 733, pp.95. ⟨10.1088/0004-637X/733/2/95⟩. ⟨hal-03730808⟩