Year: 2010
Type: article
Abstract: We have measured solar-like oscillations in red giants using time-series photometry from the first 34 days of science operations of the Kepler Mission . The light curves, obtained with 30 minute sampling, reveal clear oscillations in a large sample of G and K giants, extending in luminosity from the red clump down to the bottom of the giant branch. We confirm a strong correlation between the large separation of the oscillations (Δν) and the frequency of maximum power (ν max ). We focus on a sample of 50 low-luminosity stars (ν max > 100 μHz, L ≲ 30 L ☉ ) having high signal-to-noise ratios and showing the unambiguous signature of solar-like oscillations. These are H-shell-burning stars, whose oscillations should be valuable for testing models of stellar evolution and for constraining the star formation rate in the local disk. We use a new technique to compare stars on a single échelle diagram by scaling their frequencies and find well-defined ridges corresponding to radial and non-radial oscillations, including clear evidence for modes with angular degree l = 3. Measuring the small separation between l = 0 and l = 2 allows us to plot the so-called C-D diagram of δν 02 versus Δν. The small separation δν 01 of l = 1 from the midpoint of adjacent l = 0 modes is negative, contrary to the Sun and solar-type stars. The ridge for l = 1 is notably broadened, which we attribute to mixed modes, confirming theoretical predictions for low-luminosity giants. Overall, the results demonstrate the tremendous potential of Kepler data for asteroseismology of red giants.
Authors: T. R. Bedding, D. Huber, D. Stello, Y. P. Elsworth, S. Hekker, T. Kallinger, S. Mathur, B. Mosser, H. L. Preston, J. Ballot, C. Barban, A. M. Broomhall, D. L. Buzasi, W. J. Chaplin, R. A. García, M. Gruberbauer, S. J. Hale, J. De Ridder, S. Frandsen, W. J. Borucki, T. Brown, J. Christensen-Dalsgaard, R. L. Gilliland, J. M. Jenkins, H. Kjeldsen, D. Koch, K. Belkacem, L. Bildsten, H. Bruntt, T. L. Campante, S. Deheuvels, A. Derekas, M.-A. Dupret, M.-J. Goupil, A. Hatzes, G. Houdek, M. J. Ireland, C. Jiang, C. Karoff, L. L. Kiss, Y. Lebreton, A. Miglio, J. Montalbán, A. Noels, I. W. Roxburgh, V. Sangaralingam, I. R. Stevens, M. D. Suran, N. J. Tarrant, A. Weiss
Institutions: The University of Sydney, University of Birmingham, University of Vienna, University of British Columbia, Indian Institute of Astrophysics, Centre National de la Recherche Scientifique, Observatoire de Paris, Laboratoire d’études spatiales et d’instrumentation en astrophysique, Université Pierre-et-Marie-Curie, University of South Africa, Eureka Scientific, Université de Toulouse, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Astrophysique, Instrumentation et Modélisation, Institut de Recherche sur les Lois Fondamentales de l'Univers, Saint Mary's University, KU Leuven, Aarhus University, Ames Research Center, Las Cumbres Observatory Global Telescope Network, Space Telescope Science Institute, Search for Extraterrestrial Intelligence, University of Liège, University of California, Santa Barbara, Kavli Institute for Theoretical Physics, Universidade do Porto, Centro de Astrofísica da Universidade do Porto, Konkoly Observatory, Hungarian Academy of Sciences, Thüringer Landessternwarte Tautenburg, Beijing Normal University, Queen Mary University of London, Romanian Academy, Max Planck Institute for Astrophysics
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2102858822