Solar-Like Oscillations in Low-Luminosity Red Giants: First Results From Kepler

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Solar-Like Oscillations in Low-Luminosity Red Giants: First Results From Kepler. / Kepler Group.

In: Astrophysical Journal Letters, Vol. 713, No. 2, 20.04.2010, p. L176-L181.

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@article{ed5bedad4f64435ea1b5cdf1949856b8,
title = "Solar-Like Oscillations in Low-Luminosity Red Giants:: First Results From Kepler",
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 (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.",
keywords = "stars: individual (KIC8410637), techniques: photometric, stars: fundamental parameters, stars: individual (Procyon A), stars: oscillations, binaries: eclipsing, methods: data analysis, stars: interiors, open clusters and associations: individual (NGC 6819)",
author = "TR Bedding and Yvonne Elsworth and Saskia Hekker and Anne-Marie Broomhall and William Chaplin and Steven Hale and Ian Stevens and Neil Tarrant and {Kepler Group}",
year = "2010",
month = apr,
day = "20",
doi = "10.1088/2041-8205/713/2/L176",
language = "English",
volume = "713",
pages = "L176--L181",
journal = "Astrophysical Journal Letters",
issn = "2041-8205",
publisher = "Institute of Physics Publishing Ltd",
number = "2",

}

RIS

TY - JOUR

T1 - Solar-Like Oscillations in Low-Luminosity Red Giants:

T2 - First Results From Kepler

AU - Bedding, TR

AU - Elsworth, Yvonne

AU - Hekker, Saskia

AU - Broomhall, Anne-Marie

AU - Chaplin, William

AU - Hale, Steven

AU - Stevens, Ian

AU - Tarrant, Neil

AU - Kepler Group

PY - 2010/4/20

Y1 - 2010/4/20

N2 - 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.

AB - 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.

KW - stars: individual (KIC8410637)

KW - techniques: photometric

KW - stars: fundamental parameters

KW - stars: individual (Procyon A)

KW - stars: oscillations

KW - binaries: eclipsing

KW - methods: data analysis

KW - stars: interiors

KW - open clusters and associations: individual (NGC 6819)

U2 - 10.1088/2041-8205/713/2/L176

DO - 10.1088/2041-8205/713/2/L176

M3 - Article

VL - 713

SP - L176-L181

JO - Astrophysical Journal Letters

JF - Astrophysical Journal Letters

SN - 2041-8205

IS - 2

ER -