SOLAR-LIKE OSCILLATIONS IN LOW-LUMINOSITY RED GIANTS: FIRST RESULTS FROM KEPLER

• Type: Article in International Scientific Journal
• Date: 2010

Authors

Bedding, TR (Author) Other; Huber, D (Author) Other; Stello, D (Author) Other; Elsworth, YP (Author) Other; Hekker, S (Author) Other; Kallinger, T (Author) Other; Mathur, S (Author) Other; Mosser, B (Author) Other; Preston, HL (Author) Other; Ballot, J (Author) Other; Barban, C (Author) Other; Broomhall, AM (Author) Other; Buzasi, DL (Author) Other; Chaplin, WJ (Author) Other; Garcia, RA (Author) Other; Gruberbauer, M (Author) Other; Hale, SJ (Author) Other; De Ridder, J (Author) Other; Frandsen, S (Author) Other; Borucki, WJ (Author) Other; Brown, T (Author) Other; Christensen Dalsgaard, J (Author) Other; Gilliland, RL (Author) Other; Jenkins, JM (Author) Other; Kjeldsen, H (Author) Other; Koch, D (Author) Other; Belkacem, K (Author) Other; Bildsten, L (Author) Other; Bruntt, H (Author) Other; Campante, TL (Author) Other; Deheuvels, S (Author) Other; Derekas, A (Author) Other; Dupret, MA (Author) Other; Goupil, MJ (Author) Other; Hatzes, A (Author) Other; Houdek, G (Author) Other; Ireland, MJ (Author) Other; Jiang, C (Author) Other; Karoff, C (Author) Other; Kiss, LL (Author) Other; Lebreton, Y (Author) Other; Miglio, A (Author) Other; Montalban, J (Author) Other; Noels, A (Author) Other; Roxburgh, IW (Author) Other; Sangaralingam, V (Author) Other; Stevens, IR (Author) Other; Suran, MD (Author) Other; Tarrant, NJ (Author) Other; Weiss, A (Author) Other

Journal

Title: Astrophysical Journal Letters

Vol. 713

Pages: L176-L181

ISSN: 2041-8205

Publisher: American Astronomical Society

Indexing

ISI Web of Knowledge - 177 Citations

ISI Web of Science

Scopus - 133 Citations

Scientific classification

FOS: Natural sciences > Physical sciences

CORDIS: Physical sciences > Astronomy ; Physical sciences > Astronomy > Astrophysics

Other information

Authenticus ID: P-003-7ED

DOI: 10.1088/2041-8205/713/2/l176

Abstract (EN): 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 (Delta nu) and the frequency of maximum power (nu(max)). We focus on a sample of 50 low-luminosity stars (nu(max) > 100 mu Hz, L less than or similar to 30 L(circle dot)) 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 echelle 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 delta nu(02) versus Delta nu. The small separation delta nu(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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6