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

2010/01/22 by T. R. Bedding, D. Huber, D. Stello +51 · 6 citations
Physics and Astronomy · Social Sciences · #Asteroseismology #Astronomy and Astrophysical Research #Diagram #Educational Leadership and Practices #Luminosity #Red clump #Red giant #Ridge #Stars #Stellar, planetary, and galactic studies #astro-ph.SR

paper · pdf · doi:10.1088/2041-8205/713/2/l176

accepted by ApJ Letters, to appear in special Kepler issue. Updated references

arxiv created 2010/01/22 · openalex publication_date 2010/03/31 · arxiv updated 2015/05/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

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.

Citations

• Oscillations in Arcturus from WIRE Photometry
• PHOTOMETRIC OSCILLATIONS OF LOW-LUMINOSITY RED GIANT STARS
• Multisite campaign on the open cluster M67 - II. Evidence for solar-like oscillations in red giant stars

Cited by

• Fast core rotation in red-giant stars as revealed by gravity-dominated mixed modes
• KEPLER MISSION DESIGN, REALIZED PHOTOMETRIC PERFORMANCE, AND EARLY SCIENCE
• DISCOVERY OF A RED GIANT WITH SOLAR-LIKE OSCILLATIONS IN AN ECLIPSING BINARY SYSTEM FROM KEPLER SPACE-BASED PHOTOMETRY
• AUTOMATED CLASSIFICATION OF VARIABLE STARS IN THE ASTEROSEISMOLOGY PROGRAM OF THE KEPLER SPACE MISSION
• Spin down of the core rotation in red giants
• Stellar hydrodynamics caught in the act: Asteroseismology with CoRoT and Kepler
• Models of red giants in the CoRoT asteroseismology fields combining asteroseismic and spectroscopic constraints

Related

• Kepler asteroseismology of red-giant stars
• PHOTOMETRIC OSCILLATIONS OF LOW-LUMINOSITY RED GIANT STARS
• DETECTION OF SOLAR-LIKE OSCILLATIONS FROM KEPLER PHOTOMETRY OF THE OPEN CLUSTER NGC 6819
• THE ASTEROSEISMIC POTENTIAL OF KEPLER : FIRST RESULTS FOR SOLAR-TYPE STARS
• Detection of Solar-like Oscillations in Sub-giant and Red Giant Stars Using 2-minute Cadence TESS Data