Publications

ORCiD ID: 0000-0002-6402-8382

Full publication list is available on Google Scholar.

  • {Davies}, G. ~R., A. ~M. {Broomhall}, W. ~J. {Chaplin}, Y. {Elsworth}, and S. ~J. {Hale}. 2014. Low-frequency, low-degree solar p-mode properties from 22 years of Birmingham Solar Oscillations Network data. \mnras 439 2025-2032. doi:10.1093/mnras/stu080
    [BibTeX] [Abstract]

    {The solar low-degree low-frequency modes of oscillation are of particular interest as their frequencies can be measured with very high precision and hence provide good constraints on seismic models. Here we detect and characterize these valuable measures of the solar interior from a 22 yr Birmingham Solar Oscillations Network data set. We report mode frequencies, line widths, heights, amplitudes, and rotational splitting, all with robust uncertainties. The new values of frequency, rotational splitting, amplitude, and line width we provide will help place new constraints on hydrostatic and rotational structure, plus diagnostics of near-surface convection. Further to this, by assuming simple power laws, we extrapolate mode properties to lower frequencies. We demonstrate that the low-l low-frequency p modes have a low signal-to-noise ratio and that this cannot be overcome simply by continued observation. It will be necessary to observe the Sun in novel ways to `beat’ the intrinsic granulation noise. }

    @ARTICLE{2014MNRAS.439.2025D,
    author = {{Davies}, G.~R. and {Broomhall}, A.~M. and {Chaplin}, W.~J. and
    {Elsworth}, Y. and {Hale}, S.~J.},
    title = "{Low-frequency, low-degree solar p-mode properties from 22 years of Birmingham Solar Oscillations Network data}",
    journal = {\mnras},
    keywords = {methods: data analysis, Sun: helioseismology, Sun: oscillations},
    year = 2014,
    month = apr,
    volume = 439,
    pages = {2025-2032},
    abstract = "{The solar low-degree low-frequency modes of oscillation are of
    particular interest as their frequencies can be measured with very high
    precision and hence provide good constraints on seismic models. Here we
    detect and characterize these valuable measures of the solar interior
    from a 22 yr Birmingham Solar Oscillations Network data set. We report
    mode frequencies, line widths, heights, amplitudes, and rotational
    splitting, all with robust uncertainties. The new values of frequency,
    rotational splitting, amplitude, and line width we provide will help
    place new constraints on hydrostatic and rotational structure, plus
    diagnostics of near-surface convection. Further to this, by assuming
    simple power laws, we extrapolate mode properties to lower frequencies.
    We demonstrate that the low-l low-frequency p modes have a low
    signal-to-noise ratio and that this cannot be overcome simply by
    continued observation. It will be necessary to observe the Sun in novel
    ways to `beat' the intrinsic granulation noise.
    }",
    doi = {10.1093/mnras/stu080},
    adsurl = {http://adsabs.harvard.edu/abs/2014MNRAS.439.2025D},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Davies}, G. ~R., W. ~J. {Chaplin}, Y. {Elsworth}, and S. ~J. {Hale}. 2014. BiSON data preparation: a correction for differential extinction and the weighted averaging of contemporaneous data. \mnras 441 3009-3017. doi:10.1093/mnras/stu803
    [BibTeX] [Abstract]

    {The Birmingham Solar Oscillations Network (BiSON) has provided high-quality high-cadence observations from as far back in time as 1978. These data must be calibrated from the raw observations into radial velocity and the quality of the calibration has a large impact on the signal-to-noise ratio of the final time series. The aim of this work is to maximize the potential science that can be performed with the BiSON data set by optimizing the calibration procedure. To achieve better levels of signal-to-noise ratio, we perform two key steps in the calibration process: we attempt a correction for terrestrial atmospheric differential extinction; and the resulting improvement in the calibration allows us to perform weighted averaging of contemporaneous data from different BiSON stations. The improvements listed produce significant improvement in the signal-to-noise ratio of the BiSON frequency-power spectrum across all frequency ranges. The reduction of noise in the power spectrum will allow future work to provide greater constraint on changes in the oscillation spectrum with solar activity. In addition, the analysis of the low-frequency region suggests that we have achieved a noise level that may allow us to improve estimates of the upper limit of g-mode amplitudes. }

    @ARTICLE{2014MNRAS.441.3009D,
    author = {{Davies}, G.~R. and {Chaplin}, W.~J. and {Elsworth}, Y. and
    {Hale}, S.~J.},
    title = "{BiSON data preparation: a correction for differential extinction and the weighted averaging of contemporaneous data}",
    journal = {\mnras},
    archivePrefix = "arXiv",
    eprint = {1405.0160},
    primaryClass = "astro-ph.SR",
    keywords = {methods: data analysis, Sun: helioseismology, Sun: oscillations},
    year = 2014,
    month = jul,
    volume = 441,
    pages = {3009-3017},
    abstract = "{The Birmingham Solar Oscillations Network (BiSON) has provided
    high-quality high-cadence observations from as far back in time as 1978.
    These data must be calibrated from the raw observations into radial
    velocity and the quality of the calibration has a large impact on the
    signal-to-noise ratio of the final time series. The aim of this work is
    to maximize the potential science that can be performed with the BiSON
    data set by optimizing the calibration procedure. To achieve better
    levels of signal-to-noise ratio, we perform two key steps in the
    calibration process: we attempt a correction for terrestrial atmospheric
    differential extinction; and the resulting improvement in the
    calibration allows us to perform weighted averaging of contemporaneous
    data from different BiSON stations. The improvements listed produce
    significant improvement in the signal-to-noise ratio of the BiSON
    frequency-power spectrum across all frequency ranges. The reduction of
    noise in the power spectrum will allow future work to provide greater
    constraint on changes in the oscillation spectrum with solar activity.
    In addition, the analysis of the low-frequency region suggests that we
    have achieved a noise level that may allow us to improve estimates of
    the upper limit of g-mode amplitudes.
    }",
    doi = {10.1093/mnras/stu803},
    adsurl = {http://adsabs.harvard.edu/abs/2014MNRAS.441.3009D},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Mathur}, S., T. ~L. {Campante}, R. {Handberg}, R. ~A. {García}, T. {Appourchaux}, T. ~R. {Bedding}, B. {Mosser}, W. ~J. {Chaplin}, J. {Ballot}, O. {Benomar}, A. {Bonanno}, E. {Corsaro}, P. {Gaulme}, S. {Hekker}, C. {Régulo}, D. {Salabert}, G. {Verner}, T. ~R. {White}, I. ~M. {Brandão}, O. ~L. {Creevey}, G. {Dogan}, M. {Bazot}, M. ~S. {Cunha}, Y. {Elsworth}, D. {Huber}, S. ~J. {Hale}, G. {Houdek}, C. {Karoff}, M. {Lundkvist}, T. ~S. {Metcalfe}, J. {Molenda-Zakowicz}, M. ~J. ~P. ~F. ~G. {Monteiro}, M. ~J. {Thompson}, D. {Stello}, J. {Christensen-Dalsgaard}, R. ~L. {Gilliland}, S. ~D. {Kawaler}, H. {Kjeldsen}, B. ~D. {Clarke}, F. ~R. {Girouard}, J. ~R. {Hall}, E. ~V. {Quintana}, D. ~T. {Sanderfer}, and S. ~E. {Seader}. 2012. Seismic Analysis of Four Solar-like Stars Observed during More Than Eight Months by Kepler. Paper read at Progress in solar/stellar physics with helio- and asteroseismology.
    [BibTeX] [Abstract]

    {Having started science operations in May 2009, the Kepler photometer has been able to provide exquisite data for solar-like stars. Five out of the 42 stars observed continuously during the survey phase show evidence of oscillations, even though they are rather faint (magnitudes from 10.5 to 12). In this paper, we present an overview of the results of the seismic analysis of 4 of these stars observed during more than eight months. }

    @INPROCEEDINGS{2012ASPC..462..180M,
    author = {{Mathur}, S. and {Campante}, T.~L. and {Handberg}, R. and {Garc{\'{\i}}a}, R.~A. and
    {Appourchaux}, T. and {Bedding}, T.~R. and {Mosser}, B. and
    {Chaplin}, W.~J. and {Ballot}, J. and {Benomar}, O. and {Bonanno}, A. and
    {Corsaro}, E. and {Gaulme}, P. and {Hekker}, S. and {R{\'e}gulo}, C. and
    {Salabert}, D. and {Verner}, G. and {White}, T.~R. and {Brand{\~a}o}, I.~M. and
    {Creevey}, O.~L. and {Dogan}, G. and {Bazot}, M. and {Cunha}, M.~S. and
    {Elsworth}, Y. and {Huber}, D. and {Hale}, S.~J. and {Houdek}, G. and
    {Karoff}, C. and {Lundkvist}, M. and {Metcalfe}, T.~S. and {Molenda-Zakowicz}, J. and
    {Monteiro}, M.~J.~P.~F.~G. and {Thompson}, M.~J. and {Stello}, D. and
    {Christensen-Dalsgaard}, J. and {Gilliland}, R.~L. and {Kawaler}, S.~D. and
    {Kjeldsen}, H. and {Clarke}, B.~D. and {Girouard}, F.~R. and
    {Hall}, J.~R. and {Quintana}, E.~V. and {Sanderfer}, D.~T. and
    {Seader}, S.~E.},
    title = "{Seismic Analysis of Four Solar-like Stars Observed during More Than Eight Months by Kepler}",
    booktitle = {Progress in Solar/Stellar Physics with Helio- and Asteroseismology},
    year = 2012,
    series = {Astronomical Society of the Pacific Conference Series},
    volume = 462,
    archivePrefix = "arXiv",
    eprint = {1110.0135},
    primaryClass = "astro-ph.SR",
    editor = {{Shibahashi}, H. and {Takata}, M. and {Lynas-Gray}, A.~E.},
    month = sep,
    pages = {180},
    abstract = "{Having started science operations in May 2009, the Kepler photometer has
    been able to provide exquisite data for solar-like stars. Five out of
    the 42 stars observed continuously during the survey phase show
    evidence of oscillations, even though they are rather faint (magnitudes
    from 10.5 to 12). In this paper, we present an overview of the results
    of the seismic analysis of 4 of these stars observed during more than
    eight months.
    }",
    adsurl = {http://adsabs.harvard.edu/abs/2012ASPC..462..180M},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Mathur}, S., S. {Hekker}, R. {Trampedach}, J. {Ballot}, T. {Kallinger}, D. {Buzasi}, R. ~A. {García}, D. {Huber}, A. {Jiménez}, B. {Mosser}, T. ~R. {Bedding}, Y. {Elsworth}, C. {Régulo}, D. {Stello}, W. ~J. {Chaplin}, J. {De Ridder}, S. ~J. {Hale}, K. {Kinemuchi}, H. {Kjeldsen}, F. {Mullally}, and S. ~E. {Thompson}. 2012. Investigating the Properties of Granulation in the Red Giants Observed by Kepler. Paper read at Progress in solar/stellar physics with helio- and asteroseismology.
    [BibTeX] [Abstract]

    {More than 1000 red giants have been observed by NASA/Kepler mission during a nearly continuous period of {\tilde} 13 months. The resulting high-frequency resolution (łt 0.03 {$\mu$}Hz) allows us to study the granulation parameters of these stars. The granulation pattern results from the convection motions leading to upward flows of hot plasma and downward flows of cooler plasma. We fitted Harvey-like functions to the power spectra, to retrieve the timescale and amplitude of granulation. We show that there is an anti-correlation between both of these parameters and the position of maximum power of acoustic modes, while we also find a correlation with the radius, which agrees with the theory. We finally compare our results with 3D models of the convection. }

    @INPROCEEDINGS{2012ASPC..462..375M,
    author = {{Mathur}, S. and {Hekker}, S. and {Trampedach}, R. and {Ballot}, J. and
    {Kallinger}, T. and {Buzasi}, D. and {Garc{\'{\i}}a}, R.~A. and
    {Huber}, D. and {Jim{\'e}nez}, A. and {Mosser}, B. and {Bedding}, T.~R. and
    {Elsworth}, Y. and {R{\'e}gulo}, C. and {Stello}, D. and {Chaplin}, W.~J. and
    {De Ridder}, J. and {Hale}, S.~J. and {Kinemuchi}, K. and {Kjeldsen}, H. and
    {Mullally}, F. and {Thompson}, S.~E.},
    title = "{Investigating the Properties of Granulation in the Red Giants Observed by Kepler}",
    booktitle = {Progress in Solar/Stellar Physics with Helio- and Asteroseismology},
    year = 2012,
    series = {Astronomical Society of the Pacific Conference Series},
    volume = 462,
    archivePrefix = "arXiv",
    eprint = {1110.0117},
    primaryClass = "astro-ph.SR",
    editor = {{Shibahashi}, H. and {Takata}, M. and {Lynas-Gray}, A.~E.},
    month = sep,
    pages = {375},
    abstract = "{More than 1000 red giants have been observed by NASA/Kepler mission
    during a nearly continuous period of {\tilde} 13 months. The resulting
    high-frequency resolution ({\lt} 0.03 {$\mu$}Hz) allows us to study the
    granulation parameters of these stars. The granulation pattern results
    from the convection motions leading to upward flows of hot plasma and
    downward flows of cooler plasma. We fitted Harvey-like functions to the
    power spectra, to retrieve the timescale and amplitude of granulation.
    We show that there is an anti-correlation between both of these
    parameters and the position of maximum power of acoustic modes, while we
    also find a correlation with the radius, which agrees with the theory.
    We finally compare our results with 3D models of the convection.
    }",
    adsurl = {http://adsabs.harvard.edu/abs/2012ASPC..462..375M},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Carter}, J. ~A., E. {Agol}, W. ~J. {Chaplin}, S. {Basu}, T. ~R. {Bedding}, L. ~A. {Buchhave}, J. {Christensen-Dalsgaard}, K. ~M. {Deck}, Y. {Elsworth}, D. ~C. {Fabrycky}, E. ~B. {Ford}, J. ~J. {Fortney}, S. ~J. {Hale}, R. {Handberg}, S. {Hekker}, M. ~J. {Holman}, D. {Huber}, C. {Karoff}, S. ~D. {Kawaler}, H. {Kjeldsen}, J. ~J. {Lissauer}, E. ~D. {Lopez}, M. ~N. {Lund}, M. {Lundkvist}, T. ~S. {Metcalfe}, A. {Miglio}, L. ~A. {Rogers}, D. {Stello}, W. ~J. {Borucki}, S. {Bryson}, J. ~L. {Christiansen}, W. ~D. {Cochran}, J. ~C. {Geary}, R. ~L. {Gilliland}, M. ~R. {Haas}, J. {Hall}, A. ~W. {Howard}, J. ~M. {Jenkins}, T. {Klaus}, D. ~G. {Koch}, D. ~W. {Latham}, P. ~J. {MacQueen}, D. {Sasselov}, J. ~H. {Steffen}, J. ~D. {Twicken}, and J. ~N. {Winn}. 2012. Kepler-36: A Pair of Planets with Neighboring Orbits and Dissimilar Densities. Science 337 556-. doi:10.1126/science.1223269
    [BibTeX] [Abstract]

    {In the solar system, the planets{\rsquo} compositions vary with orbital distance, with rocky planets in close orbits and lower-density gas giants in wider orbits. The detection of close-in giant planets around other stars was the first clue that this pattern is not universal and that planets{\rsquo} orbits can change substantially after their formation. Here, we report another violation of the orbit-composition pattern: two planets orbiting the same star with orbital distances differing by only 10\% and densities differing by a factor of 8. One planet is likely a rocky {\ldquo}super-Earth,{\rdquo} whereas the other is more akin to Neptune. These planets are 20 times more closely spaced and have a larger density contrast than any adjacent pair of planets in the solar system. }

    @ARTICLE{2012Sci...337..556C,
    author = {{Carter}, J.~A. and {Agol}, E. and {Chaplin}, W.~J. and {Basu}, S. and
    {Bedding}, T.~R. and {Buchhave}, L.~A. and {Christensen-Dalsgaard}, J. and
    {Deck}, K.~M. and {Elsworth}, Y. and {Fabrycky}, D.~C. and {Ford}, E.~B. and
    {Fortney}, J.~J. and {Hale}, S.~J. and {Handberg}, R. and {Hekker}, S. and
    {Holman}, M.~J. and {Huber}, D. and {Karoff}, C. and {Kawaler}, S.~D. and
    {Kjeldsen}, H. and {Lissauer}, J.~J. and {Lopez}, E.~D. and
    {Lund}, M.~N. and {Lundkvist}, M. and {Metcalfe}, T.~S. and
    {Miglio}, A. and {Rogers}, L.~A. and {Stello}, D. and {Borucki}, W.~J. and
    {Bryson}, S. and {Christiansen}, J.~L. and {Cochran}, W.~D. and
    {Geary}, J.~C. and {Gilliland}, R.~L. and {Haas}, M.~R. and
    {Hall}, J. and {Howard}, A.~W. and {Jenkins}, J.~M. and {Klaus}, T. and
    {Koch}, D.~G. and {Latham}, D.~W. and {MacQueen}, P.~J. and
    {Sasselov}, D. and {Steffen}, J.~H. and {Twicken}, J.~D. and
    {Winn}, J.~N.},
    title = "{Kepler-36: A Pair of Planets with Neighboring Orbits and Dissimilar Densities}",
    journal = {Science},
    archivePrefix = "arXiv",
    eprint = {1206.4718},
    primaryClass = "astro-ph.EP",
    year = 2012,
    month = aug,
    volume = 337,
    pages = {556-},
    abstract = "{In the solar system, the planets{\rsquo} compositions vary with orbital
    distance, with rocky planets in close orbits and lower-density gas
    giants in wider orbits. The detection of close-in giant planets around
    other stars was the first clue that this pattern is not universal and
    that planets{\rsquo} orbits can change substantially after their
    formation. Here, we report another violation of the orbit-composition
    pattern: two planets orbiting the same star with orbital distances
    differing by only 10\% and densities differing by a factor of 8. One
    planet is likely a rocky {\ldquo}super-Earth,{\rdquo} whereas the other is
    more akin to Neptune. These planets are 20 times more closely spaced and
    have a larger density contrast than any adjacent pair of planets in the
    solar system.
    }",
    doi = {10.1126/science.1223269},
    adsurl = {http://adsabs.harvard.edu/abs/2012Sci...337..556C},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Hekker}, S., S. {Basu}, D. {Stello}, T. {Kallinger}, F. {Grundahl}, S. {Mathur}, R. ~A. {García}, B. {Mosser}, D. {Huber}, T. ~R. {Bedding}, R. {Szabó}, J. {De Ridder}, W. ~J. {Chaplin}, Y. {Elsworth}, S. ~J. {Hale}, J. {Christensen-Dalsgaard}, R. ~L. {Gilliland}, M. {Still}, S. {McCauliff}, and E. ~V. {Quintana}. 2011. Asteroseismic inferences on red giants in open clusters NGC 6791, NGC 6819, and NGC 6811 using Kepler. \aap 530 A100. doi:10.1051/0004-6361/201016303
    [BibTeX] [Abstract]

    {Context. Four open clusters are present in the Kepler field of view and timeseries of nearly a year in length are now available. These timeseries allow us to derive asteroseismic global oscillation parameters of red-giant stars in the three open clusters NGC 6791, NGC 6819 and NGC 6811. From these parameters and effective temperatures, we derive masses, radii and luminosities for the clusters as well as field red giants. <BR /> Aims: We study the influence of evolution and metallicity on the observed red-giant populations. <BR /> Methods: The global oscillation parameters are derived using different published methods and the effective temperatures are derived from 2MASS colours. The observational results are compared with BaSTI evolution models. <BR /> Results: We find that the mass has significant influence on the asteroseismic quantities {$\Delta$}{$\nu$} vs. {$\nu$}$_{max}$ relation, while the influence of metallicity is negligible, under the assumption that the metallicity does not affect the excitation/damping of the oscillations. The positions of the stars in the H-R diagram depend on both mass and metallicity. Furthermore, the stellar masses derived for the field stars are bracketed by those of the cluster stars. <BR /> Conclusions: Both the mass and metallicity contribute to the observed difference in locations in the H-R diagram of the old metal-rich cluster NGC 6791 and the middle-aged solar-metallicity cluster NGC 6819. For the young cluster NGC 6811, the explanation of the position of the stars in the H-R diagram challenges the assumption of solar metallicity, and this open cluster might have significantly lower metallicity [Fe/H] in the range – 0.3 to – 0.7 dex. Also, nearly all the observed field stars seem to be older than NGC 6811 and younger than NGC 6791. }

    @ARTICLE{2011A&A...530A.100H,
    author = {{Hekker}, S. and {Basu}, S. and {Stello}, D. and {Kallinger}, T. and
    {Grundahl}, F. and {Mathur}, S. and {Garc{\'{\i}}a}, R.~A. and
    {Mosser}, B. and {Huber}, D. and {Bedding}, T.~R. and {Szab{\'o}}, R. and
    {De Ridder}, J. and {Chaplin}, W.~J. and {Elsworth}, Y. and
    {Hale}, S.~J. and {Christensen-Dalsgaard}, J. and {Gilliland}, R.~L. and
    {Still}, M. and {McCauliff}, S. and {Quintana}, E.~V.},
    title = "{Asteroseismic inferences on red giants in open clusters NGC 6791, NGC 6819, and NGC 6811 using Kepler}",
    journal = {\aap},
    archivePrefix = "arXiv",
    eprint = {1104.4393},
    primaryClass = "astro-ph.SR",
    keywords = {stars: late-type, open clusters and associations: general, methods: observational, techniques: photometric, asteroseismology},
    year = 2011,
    month = jun,
    volume = 530,
    eid = {A100},
    pages = {A100},
    abstract = "{Context. Four open clusters are present in the Kepler field of view and
    timeseries of nearly a year in length are now available. These
    timeseries allow us to derive asteroseismic global oscillation
    parameters of red-giant stars in the three open clusters NGC 6791, NGC
    6819 and NGC 6811. From these parameters and effective temperatures, we
    derive masses, radii and luminosities for the clusters as well as field
    red giants. <BR /> Aims: We study the influence of evolution and
    metallicity on the observed red-giant populations. <BR /> Methods: The
    global oscillation parameters are derived using different published
    methods and the effective temperatures are derived from 2MASS colours.
    The observational results are compared with BaSTI evolution models. <BR
    /> Results: We find that the mass has significant influence on the
    asteroseismic quantities {$\Delta$}{$\nu$} vs. {$\nu$}$_{max}$ relation,
    while the influence of metallicity is negligible, under the assumption
    that the metallicity does not affect the excitation/damping of the
    oscillations. The positions of the stars in the H-R diagram depend on
    both mass and metallicity. Furthermore, the stellar masses derived for
    the field stars are bracketed by those of the cluster stars. <BR />
    Conclusions: Both the mass and metallicity contribute to the observed
    difference in locations in the H-R diagram of the old metal-rich cluster
    NGC 6791 and the middle-aged solar-metallicity cluster NGC 6819. For the
    young cluster NGC 6811, the explanation of the position of the stars in
    the H-R diagram challenges the assumption of solar metallicity, and this
    open cluster might have significantly lower metallicity [Fe/H] in the
    range - 0.3 to - 0.7 dex. Also, nearly all the observed field stars seem
    to be older than NGC 6811 and younger than NGC 6791.
    }",
    doi = {10.1051/0004-6361/201016303},
    adsurl = {http://adsabs.harvard.edu/abs/2011A%26A...530A.100H},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Chaplin}, W. ~J., H. {Kjeldsen}, T. ~R. {Bedding}, J. {Christensen-Dalsgaard}, R. ~L. {Gilliland}, S. ~D. {Kawaler}, T. {Appourchaux}, Y. {Elsworth}, R. ~A. {García}, G. {Houdek}, C. {Karoff}, T. ~S. {Metcalfe}, J. {Molenda-Żakowicz}, M. ~J. ~P. ~F. ~G. {Monteiro}, M. ~J. {Thompson}, G. ~A. {Verner}, N. {Batalha}, W. ~J. {Borucki}, T. ~M. {Brown}, S. ~T. {Bryson}, J. ~L. {Christiansen}, B. ~D. {Clarke}, J. ~M. {Jenkins}, T. ~C. {Klaus}, D. {Koch}, D. {An}, J. {Ballot}, S. {Basu}, O. {Benomar}, A. {Bonanno}, A. -M. {Broomhall}, T. ~L. {Campante}, E. {Corsaro}, O. ~L. {Creevey}, L. {Esch}, N. {Gai}, P. {Gaulme}, S. ~J. {Hale}, R. {Handberg}, S. {Hekker}, D. {Huber}, S. {Mathur}, B. {Mosser}, R. {New}, M. ~H. {Pinsonneault}, D. {Pricopi}, P. -O. {Quirion}, C. {Régulo}, I. ~W. {Roxburgh}, D. {Salabert}, D. {Stello}, and M. ~D. {Suran}. 2011. Predicting the Detectability of Oscillations in Solar-type Stars Observed by Kepler. \apj 732 54. doi:10.1088/0004-637X/732/1/54
    [BibTeX] [Abstract]

    {Asteroseismology of solar-type stars has an important part to play in the exoplanet program of the NASA Kepler Mission. Precise and accurate inferences on the stellar properties that are made possible by the seismic data allow very tight constraints to be placed on the exoplanetary systems. Here, we outline how to make an estimate of the detectability of solar-like oscillations in any given Kepler target, using rough estimates of the temperature and radius, and the Kepler apparent magnitude. }

    @ARTICLE{2011ApJ...732...54C,
    author = {{Chaplin}, W.~J. and {Kjeldsen}, H. and {Bedding}, T.~R. and
    {Christensen-Dalsgaard}, J. and {Gilliland}, R.~L. and {Kawaler}, S.~D. and
    {Appourchaux}, T. and {Elsworth}, Y. and {Garc{\'{\i}}a}, R.~A. and
    {Houdek}, G. and {Karoff}, C. and {Metcalfe}, T.~S. and {Molenda-{\.Z}akowicz}, J. and
    {Monteiro}, M.~J.~P.~F.~G. and {Thompson}, M.~J. and {Verner}, G.~A. and
    {Batalha}, N. and {Borucki}, W.~J. and {Brown}, T.~M. and {Bryson}, S.~T. and
    {Christiansen}, J.~L. and {Clarke}, B.~D. and {Jenkins}, J.~M. and
    {Klaus}, T.~C. and {Koch}, D. and {An}, D. and {Ballot}, J. and
    {Basu}, S. and {Benomar}, O. and {Bonanno}, A. and {Broomhall}, A.-M. and
    {Campante}, T.~L. and {Corsaro}, E. and {Creevey}, O.~L. and
    {Esch}, L. and {Gai}, N. and {Gaulme}, P. and {Hale}, S.~J. and
    {Handberg}, R. and {Hekker}, S. and {Huber}, D. and {Mathur}, S. and
    {Mosser}, B. and {New}, R. and {Pinsonneault}, M.~H. and {Pricopi}, D. and
    {Quirion}, P.-O. and {R{\'e}gulo}, C. and {Roxburgh}, I.~W. and
    {Salabert}, D. and {Stello}, D. and {Suran}, M.~D.},
    title = "{Predicting the Detectability of Oscillations in Solar-type Stars Observed by Kepler}",
    journal = {\apj},
    archivePrefix = "arXiv",
    eprint = {1103.0702},
    primaryClass = "astro-ph.SR",
    keywords = {stars: interiors, stars: late-type, stars: oscillations},
    year = 2011,
    month = may,
    volume = 732,
    eid = {54},
    pages = {54},
    abstract = "{Asteroseismology of solar-type stars has an important part to play in
    the exoplanet program of the NASA Kepler Mission. Precise and accurate
    inferences on the stellar properties that are made possible by the
    seismic data allow very tight constraints to be placed on the
    exoplanetary systems. Here, we outline how to make an estimate of the
    detectability of solar-like oscillations in any given Kepler target,
    using rough estimates of the temperature and radius, and the Kepler
    apparent magnitude.
    }",
    doi = {10.1088/0004-637X/732/1/54},
    adsurl = {http://adsabs.harvard.edu/abs/2011ApJ...732...54C},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Chaplin}, W. ~J., T. ~R. {Bedding}, A. {Bonanno}, A. -M. {Broomhall}, R. ~A. {García}, S. {Hekker}, D. {Huber}, G. ~A. {Verner}, S. {Basu}, Y. {Elsworth}, G. {Houdek}, S. {Mathur}, B. {Mosser}, R. {New}, I. ~R. {Stevens}, T. {Appourchaux}, C. {Karoff}, T. ~S. {Metcalfe}, J. {Molenda-Żakowicz}, M. ~J. ~P. ~F. ~G. {Monteiro}, M. ~J. {Thompson}, J. {Christensen-Dalsgaard}, R. ~L. {Gilliland}, S. ~D. {Kawaler}, H. {Kjeldsen}, J. {Ballot}, O. {Benomar}, E. {Corsaro}, T. ~L. {Campante}, P. {Gaulme}, S. ~J. {Hale}, R. {Handberg}, E. {Jarvis}, C. {Régulo}, I. ~W. {Roxburgh}, D. {Salabert}, D. {Stello}, F. {Mullally}, J. {Li}, and W. {Wohler}. 2011. Evidence for the Impact of Stellar Activity on the Detectability of Solar-like Oscillations Observed by Kepler. \apjl 732 L5. doi:10.1088/2041-8205/732/1/L5
    [BibTeX] [Abstract]

    {We use photometric observations of solar-type stars, made by the NASA Kepler Mission, to conduct a statistical study of the impact of stellar surface activity on the detectability of solar-like oscillations. We find that the number of stars with detected oscillations falls significantly with increasing levels of activity. The results present strong evidence for the impact of magnetic activity on the properties of near-surface convection in the stars, which appears to inhibit the amplitudes of the stochastically excited, intrinsically damped solar-like oscillations. }

    @ARTICLE{2011ApJ...732L...5C,
    author = {{Chaplin}, W.~J. and {Bedding}, T.~R. and {Bonanno}, A. and
    {Broomhall}, A.-M. and {Garc{\'{\i}}a}, R.~A. and {Hekker}, S. and
    {Huber}, D. and {Verner}, G.~A. and {Basu}, S. and {Elsworth}, Y. and
    {Houdek}, G. and {Mathur}, S. and {Mosser}, B. and {New}, R. and
    {Stevens}, I.~R. and {Appourchaux}, T. and {Karoff}, C. and
    {Metcalfe}, T.~S. and {Molenda-{\.Z}akowicz}, J. and {Monteiro}, M.~J.~P.~F.~G. and
    {Thompson}, M.~J. and {Christensen-Dalsgaard}, J. and {Gilliland}, R.~L. and
    {Kawaler}, S.~D. and {Kjeldsen}, H. and {Ballot}, J. and {Benomar}, O. and
    {Corsaro}, E. and {Campante}, T.~L. and {Gaulme}, P. and {Hale}, S.~J. and
    {Handberg}, R. and {Jarvis}, E. and {R{\'e}gulo}, C. and {Roxburgh}, I.~W. and
    {Salabert}, D. and {Stello}, D. and {Mullally}, F. and {Li}, J. and
    {Wohler}, W.},
    title = "{Evidence for the Impact of Stellar Activity on the Detectability of Solar-like Oscillations Observed by Kepler}",
    journal = {\apjl},
    archivePrefix = "arXiv",
    eprint = {1103.5570},
    primaryClass = "astro-ph.SR",
    keywords = {stars: activity, stars: interiors, stars: late-type, stars: magnetic field, stars: oscillations},
    year = 2011,
    month = may,
    volume = 732,
    eid = {L5},
    pages = {L5},
    abstract = "{We use photometric observations of solar-type stars, made by the NASA
    Kepler Mission, to conduct a statistical study of the impact of stellar
    surface activity on the detectability of solar-like oscillations. We
    find that the number of stars with detected oscillations falls
    significantly with increasing levels of activity. The results present
    strong evidence for the impact of magnetic activity on the properties of
    near-surface convection in the stars, which appears to inhibit the
    amplitudes of the stochastically excited, intrinsically damped
    solar-like oscillations.
    }",
    doi = {10.1088/2041-8205/732/1/L5},
    adsurl = {http://adsabs.harvard.edu/abs/2011ApJ...732L...5C},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Chaplin}, W. ~J., H. {Kjeldsen}, J. {Christensen-Dalsgaard}, S. {Basu}, A. {Miglio}, T. {Appourchaux}, T. ~R. {Bedding}, Y. {Elsworth}, R. ~A. {García}, R. ~L. {Gilliland}, L. {Girardi}, G. {Houdek}, C. {Karoff}, S. ~D. {Kawaler}, T. ~S. {Metcalfe}, J. {Molenda-Żakowicz}, M. ~J. ~P. ~F. ~G. {Monteiro}, M. ~J. {Thompson}, G. ~A. {Verner}, J. {Ballot}, A. {Bonanno}, I. ~M. {Brandão}, A. -M. {Broomhall}, H. {Bruntt}, T. ~L. {Campante}, E. {Corsaro}, O. ~L. {Creevey}, G. {Do{u g}an}, L. {Esch}, N. {Gai}, P. {Gaulme}, S. ~J. {Hale}, R. {Handberg}, S. {Hekker}, D. {Huber}, A. {Jiménez}, S. {Mathur}, A. {Mazumdar}, B. {Mosser}, R. {New}, M. ~H. {Pinsonneault}, D. {Pricopi}, P. -O. {Quirion}, C. {Régulo}, D. {Salabert}, A. ~M. {Serenelli}, V. {Silva Aguirre}, S. ~G. {Sousa}, D. {Stello}, I. ~R. {Stevens}, M. ~D. {Suran}, K. {Uytterhoeven}, T. ~R. {White}, W. ~J. {Borucki}, T. ~M. {Brown}, J. ~M. {Jenkins}, K. {Kinemuchi}, J. {Van Cleve}, and T. ~C. {Klaus}. 2011. Ensemble Asteroseismology of Solar-Type Stars with the NASA Kepler Mission. Science 332 213-. doi:10.1126/science.1201827
    [BibTeX] [Abstract]

    {In addition to its search for extrasolar planets, the NASA Kepler mission provides exquisite data on stellar oscillations. We report the detections of oscillations in 500 solar-type stars in the Kepler field of view, an ensemble that is large enough to allow statistical studies of intrinsic stellar properties (such as mass, radius, and age) and to test theories of stellar evolution. We find that the distribution of observed masses of these stars shows intriguing differences to predictions from models of synthetic stellar populations in the Galaxy. }

    @ARTICLE{2011Sci...332..213C,
    author = {{Chaplin}, W.~J. and {Kjeldsen}, H. and {Christensen-Dalsgaard}, J. and
    {Basu}, S. and {Miglio}, A. and {Appourchaux}, T. and {Bedding}, T.~R. and
    {Elsworth}, Y. and {Garc{\'{\i}}a}, R.~A. and {Gilliland}, R.~L. and
    {Girardi}, L. and {Houdek}, G. and {Karoff}, C. and {Kawaler}, S.~D. and
    {Metcalfe}, T.~S. and {Molenda-{\.Z}akowicz}, J. and {Monteiro}, M.~J.~P.~F.~G. and
    {Thompson}, M.~J. and {Verner}, G.~A. and {Ballot}, J. and {Bonanno}, A. and
    {Brand{\~a}o}, I.~M. and {Broomhall}, A.-M. and {Bruntt}, H. and
    {Campante}, T.~L. and {Corsaro}, E. and {Creevey}, O.~L. and
    {Do{\u g}an}, G. and {Esch}, L. and {Gai}, N. and {Gaulme}, P. and
    {Hale}, S.~J. and {Handberg}, R. and {Hekker}, S. and {Huber}, D. and
    {Jim{\'e}nez}, A. and {Mathur}, S. and {Mazumdar}, A. and {Mosser}, B. and
    {New}, R. and {Pinsonneault}, M.~H. and {Pricopi}, D. and {Quirion}, P.-O. and
    {R{\'e}gulo}, C. and {Salabert}, D. and {Serenelli}, A.~M. and
    {Silva Aguirre}, V. and {Sousa}, S.~G. and {Stello}, D. and
    {Stevens}, I.~R. and {Suran}, M.~D. and {Uytterhoeven}, K. and
    {White}, T.~R. and {Borucki}, W.~J. and {Brown}, T.~M. and {Jenkins}, J.~M. and
    {Kinemuchi}, K. and {Van Cleve}, J. and {Klaus}, T.~C.},
    title = "{Ensemble Asteroseismology of Solar-Type Stars with the NASA Kepler Mission}",
    journal = {Science},
    archivePrefix = "arXiv",
    eprint = {1109.4723},
    primaryClass = "astro-ph.SR",
    year = 2011,
    month = apr,
    volume = 332,
    pages = {213-},
    abstract = "{In addition to its search for extrasolar planets, the NASA Kepler
    mission provides exquisite data on stellar oscillations. We report the
    detections of oscillations in 500 solar-type stars in the Kepler field
    of view, an ensemble that is large enough to allow statistical studies
    of intrinsic stellar properties (such as mass, radius, and age) and to
    test theories of stellar evolution. We find that the distribution of
    observed masses of these stars shows intriguing differences to
    predictions from models of synthetic stellar populations in the Galaxy.
    }",
    doi = {10.1126/science.1201827},
    adsurl = {http://adsabs.harvard.edu/abs/2011Sci...332..213C},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Hekker}, S., Y. {Elsworth}, J. {De Ridder}, B. {Mosser}, R. ~A. {García}, T. {Kallinger}, S. {Mathur}, D. {Huber}, D. ~L. {Buzasi}, H. ~L. {Preston}, S. ~J. {Hale}, J. {Ballot}, W. ~J. {Chaplin}, C. {Régulo}, T. ~R. {Bedding}, D. {Stello}, W. ~J. {Borucki}, D. ~G. {Koch}, J. {Jenkins}, C. {Allen}, R. ~L. {Gilliland}, H. {Kjeldsen}, and J. {Christensen-Dalsgaard}. 2011. Solar-like oscillations in red giants observed with Kepler: comparison of global oscillation parameters from different methods. \aap 525 A131. doi:10.1051/0004-6361/201015185
    [BibTeX] [Abstract]

    {Context. The large number of stars for which uninterrupted high-precision photometric timeseries data are being collected with Kepler and CoRoT initiated the development of automated methods to analyse the stochastically excited oscillations in main-sequence, subgiant and red-giant stars. <BR /> Aims: We investigate the differences in results for global oscillation parameters of G and K red-giant stars due to different methods and definitions. We also investigate uncertainties originating from the stochastic nature of the oscillations. <BR /> Methods: For this investigation we use Kepler data obtained during the first four months of operation. These data have been analysed by different groups using already published methods and the results are compared. We also performed simulations to investigate the uncertainty on the resulting parameters due to different realizations of the stochastic signal. <BR /> Results: We obtain results for the frequency of maximum oscillation power ({$\nu$}_max) and the mean large separation (łt{$\Delta$}{$\nu$}{\gt}) from different methods for over one thousand red-giant stars. The results for these parameters agree within a few percent and seem therefore robust to the different analysis methods and definitions used here. The uncertainties for {$\nu$}_max and łt{$\Delta$}{$\nu$}{\gt} due to differences in realization noise are not negligible and should be taken into account when using these results for stellar modelling. Table 7 is only available in electronic form at <A href=”http://www.aanda.org”>http://www.aanda.org</A> }

    @ARTICLE{2011A&A...525A.131H,
    author = {{Hekker}, S. and {Elsworth}, Y. and {De Ridder}, J. and {Mosser}, B. and
    {Garc{\'{\i}}a}, R.~A. and {Kallinger}, T. and {Mathur}, S. and
    {Huber}, D. and {Buzasi}, D.~L. and {Preston}, H.~L. and {Hale}, S.~J. and
    {Ballot}, J. and {Chaplin}, W.~J. and {R{\'e}gulo}, C. and {Bedding}, T.~R. and
    {Stello}, D. and {Borucki}, W.~J. and {Koch}, D.~G. and {Jenkins}, J. and
    {Allen}, C. and {Gilliland}, R.~L. and {Kjeldsen}, H. and {Christensen-Dalsgaard}, J.
    },
    title = "{Solar-like oscillations in red giants observed with Kepler: comparison of global oscillation parameters from different methods}",
    journal = {\aap},
    archivePrefix = "arXiv",
    eprint = {1008.2959},
    primaryClass = "astro-ph.SR",
    keywords = {asteroseismology, stars: late-type, methods: observational, techniques: photometric},
    year = 2011,
    month = jan,
    volume = 525,
    eid = {A131},
    pages = {A131},
    abstract = "{Context. The large number of stars for which uninterrupted
    high-precision photometric timeseries data are being collected with
    Kepler and CoRoT initiated the development of automated methods to
    analyse the stochastically excited oscillations in main-sequence,
    subgiant and red-giant stars. <BR /> Aims: We investigate the
    differences in results for global oscillation parameters of G and K
    red-giant stars due to different methods and definitions. We also
    investigate uncertainties originating from the stochastic nature of the
    oscillations. <BR /> Methods: For this investigation we use Kepler data
    obtained during the first four months of operation. These data have been
    analysed by different groups using already published methods and the
    results are compared. We also performed simulations to investigate the
    uncertainty on the resulting parameters due to different realizations of
    the stochastic signal. <BR /> Results: We obtain results for the
    frequency of maximum oscillation power ({$\nu$}\_max) and the mean large
    separation ({\lt}{$\Delta$}{$\nu$}{\gt}) from different methods for over one
    thousand red-giant stars. The results for these parameters agree within
    a few percent and seem therefore robust to the different analysis
    methods and definitions used here. The uncertainties for {$\nu$}\_max and
    {\lt}{$\Delta$}{$\nu$}{\gt} due to differences in realization noise are not
    negligible and should be taken into account when using these results for
    stellar modelling.
    Table 7 is only available in electronic form at <A
    href=''http://www.aanda.org''>http://www.aanda.org</A>
    }",
    doi = {10.1051/0004-6361/201015185},
    adsurl = {http://adsabs.harvard.edu/abs/2011A%26A...525A.131H},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Huber}, D., T. ~R. {Bedding}, D. {Stello}, S. {Hekker}, S. {Mathur}, B. {Mosser}, G. ~A. {Verner}, A. {Bonanno}, D. ~L. {Buzasi}, T. ~L. {Campante}, Y. ~P. {Elsworth}, S. ~J. {Hale}, T. {Kallinger}, V. {Silva Aguirre}, W. ~J. {Chaplin}, J. {De Ridder}, R. ~A. {García}, T. {Appourchaux}, S. {Frandsen}, G. {Houdek}, J. {Molenda-Żakowicz}, M. ~J. ~P. ~F. ~G. {Monteiro}, J. {Christensen-Dalsgaard}, R. ~L. {Gilliland}, S. ~D. {Kawaler}, H. {Kjeldsen}, A. ~M. {Broomhall}, E. {Corsaro}, D. {Salabert}, D. ~T. {Sanderfer}, S. ~E. {Seader}, and J. ~C. {Smith}. 2011. Testing Scaling Relations for Solar-like Oscillations from the Main Sequence to Red Giants Using Kepler Data. \apj 743 143. doi:10.1088/0004-637X/743/2/143
    [BibTeX] [Abstract]

    {We have analyzed solar-like oscillations in \~{}1700 stars observed by the Kepler Mission, spanning from the main sequence to the red clump. Using evolutionary models, we test asteroseismic scaling relations for the frequency of maximum power ({$\nu$}$_{max}$), the large frequency separation ({$\Delta$}{$\nu$}), and oscillation amplitudes. We show that the difference of the {$\Delta$}{$\nu$}-{$\nu$}$_{max}$ relation for unevolved and evolved stars can be explained by different distributions in effective temperature and stellar mass, in agreement with what is expected from scaling relations. For oscillation amplitudes, we show that neither (L/M)$^{ s }$ scaling nor the revised scaling relation by Kjeldsen {\amp} Bedding is accurate for red-giant stars, and demonstrate that a revised scaling relation with a separate luminosity-mass dependence can be used to calculate amplitudes from the main sequence to red giants to a precision of \~{}25\%. The residuals show an offset particularly for unevolved stars, suggesting that an additional physical dependency is necessary to fully reproduce the observed amplitudes. We investigate correlations between amplitudes and stellar activity, and find evidence that the effect of amplitude suppression is most pronounced for subgiant stars. Finally, we test the location of the cool edge of the instability strip in the Hertzsprung-Russell diagram using solar-like oscillations and find the detections in the hottest stars compatible with a domain of hybrid stochastically excited and opacity driven pulsation. }

    @ARTICLE{2011ApJ...743..143H,
    author = {{Huber}, D. and {Bedding}, T.~R. and {Stello}, D. and {Hekker}, S. and
    {Mathur}, S. and {Mosser}, B. and {Verner}, G.~A. and {Bonanno}, A. and
    {Buzasi}, D.~L. and {Campante}, T.~L. and {Elsworth}, Y.~P. and
    {Hale}, S.~J. and {Kallinger}, T. and {Silva Aguirre}, V. and
    {Chaplin}, W.~J. and {De Ridder}, J. and {Garc{\'{\i}}a}, R.~A. and
    {Appourchaux}, T. and {Frandsen}, S. and {Houdek}, G. and {Molenda-{\.Z}akowicz}, J. and
    {Monteiro}, M.~J.~P.~F.~G. and {Christensen-Dalsgaard}, J. and
    {Gilliland}, R.~L. and {Kawaler}, S.~D. and {Kjeldsen}, H. and
    {Broomhall}, A.~M. and {Corsaro}, E. and {Salabert}, D. and
    {Sanderfer}, D.~T. and {Seader}, S.~E. and {Smith}, J.~C.},
    title = "{Testing Scaling Relations for Solar-like Oscillations from the Main Sequence to Red Giants Using Kepler Data}",
    journal = {\apj},
    archivePrefix = "arXiv",
    eprint = {1109.3460},
    primaryClass = "astro-ph.SR",
    keywords = {stars: late-type, stars: oscillations, techniques: photometric},
    year = 2011,
    month = dec,
    volume = 743,
    eid = {143},
    pages = {143},
    abstract = "{We have analyzed solar-like oscillations in \~{}1700 stars observed by the
    Kepler Mission, spanning from the main sequence to the red clump. Using
    evolutionary models, we test asteroseismic scaling relations for the
    frequency of maximum power ({$\nu$}$_{max}$), the large frequency
    separation ({$\Delta$}{$\nu$}), and oscillation amplitudes. We show that the
    difference of the {$\Delta$}{$\nu$}-{$\nu$}$_{max}$ relation for unevolved
    and evolved stars can be explained by different distributions in
    effective temperature and stellar mass, in agreement with what is
    expected from scaling relations. For oscillation amplitudes, we show
    that neither (L/M)$^{ s }$ scaling nor the revised scaling
    relation by Kjeldsen {\amp} Bedding is accurate for red-giant stars, and
    demonstrate that a revised scaling relation with a separate
    luminosity-mass dependence can be used to calculate amplitudes from the
    main sequence to red giants to a precision of \~{}25\%. The residuals show
    an offset particularly for unevolved stars, suggesting that an
    additional physical dependency is necessary to fully reproduce the
    observed amplitudes. We investigate correlations between amplitudes and
    stellar activity, and find evidence that the effect of amplitude
    suppression is most pronounced for subgiant stars. Finally, we test the
    location of the cool edge of the instability strip in the
    Hertzsprung-Russell diagram using solar-like oscillations and find the
    detections in the hottest stars compatible with a domain of hybrid
    stochastically excited and opacity driven pulsation.
    }",
    doi = {10.1088/0004-637X/743/2/143},
    adsurl = {http://adsabs.harvard.edu/abs/2011ApJ...743..143H},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Mathur}, S., S. {Hekker}, R. {Trampedach}, J. {Ballot}, T. {Kallinger}, D. {Buzasi}, R. ~A. {García}, D. {Huber}, A. {Jiménez}, B. {Mosser}, T. ~R. {Bedding}, Y. {Elsworth}, C. {Régulo}, D. {Stello}, W. ~J. {Chaplin}, J. {De Ridder}, S. ~J. {Hale}, K. {Kinemuchi}, H. {Kjeldsen}, F. {Mullally}, and S. ~E. {Thompson}. 2011. Granulation in Red Giants: Observations by the Kepler Mission and Three-dimensional Convection Simulations. \apj 741 119. doi:10.1088/0004-637X/741/2/119
    [BibTeX] [Abstract]

    {The granulation pattern that we observe on the surface of the Sun is due to hot plasma rising to the photosphere where it cools down and descends back into the interior at the edges of granules. This is the visible manifestation of convection taking place in the outer part of the solar convection zone. Because red giants have deeper convection zones than the Sun, we cannot a priori assume that their granulation is a scaled version of solar granulation. Until now, neither observations nor one-dimensional analytical convection models could put constraints on granulation in red giants. With asteroseismology, this study can now be performed. We analyze \~{}1000 red giants that have been observed by Kepler during 13 months. We fit the power spectra with Harvey-like profiles to retrieve the characteristics of the granulation (timescale {$\tau$}$_{gran}$ and power P $_{gran}$). We search for a correlation between these parameters and the global acoustic-mode parameter (the position of maximum power, {$\nu$}$_{max}$) as well as with stellar parameters (mass, radius, surface gravity (log g), and effective temperature (T $_{eff}$)). We show that {$\tau$}$_{eff}$vprop{$\nu$}$^{-0.89}$ $_{max}$ and P $_{gran}$vprop{$\nu$}$^{-1.90}$ $_{max}$, which is consistent with the theoretical predictions. We find that the granulation timescales of stars that belong to the red clump have similar values while the timescales of stars in the red giant branch are spread in a wider range. Finally, we show that realistic three-dimensional simulations of the surface convection in stars, spanning the (T $_{eff}$, log g) range of our sample of red giants, match the Kepler observations well in terms of trends. }

    @ARTICLE{2011ApJ...741..119M,
    author = {{Mathur}, S. and {Hekker}, S. and {Trampedach}, R. and {Ballot}, J. and
    {Kallinger}, T. and {Buzasi}, D. and {Garc{\'{\i}}a}, R.~A. and
    {Huber}, D. and {Jim{\'e}nez}, A. and {Mosser}, B. and {Bedding}, T.~R. and
    {Elsworth}, Y. and {R{\'e}gulo}, C. and {Stello}, D. and {Chaplin}, W.~J. and
    {De Ridder}, J. and {Hale}, S.~J. and {Kinemuchi}, K. and {Kjeldsen}, H. and
    {Mullally}, F. and {Thompson}, S.~E.},
    title = "{Granulation in Red Giants: Observations by the Kepler Mission and Three-dimensional Convection Simulations}",
    journal = {\apj},
    archivePrefix = "arXiv",
    eprint = {1109.1194},
    primaryClass = "astro-ph.SR",
    keywords = {methods: data analysis, stars: late-type},
    year = 2011,
    month = nov,
    volume = 741,
    eid = {119},
    pages = {119},
    abstract = "{The granulation pattern that we observe on the surface of the Sun is due
    to hot plasma rising to the photosphere where it cools down and descends
    back into the interior at the edges of granules. This is the visible
    manifestation of convection taking place in the outer part of the solar
    convection zone. Because red giants have deeper convection zones than
    the Sun, we cannot a priori assume that their granulation is a scaled
    version of solar granulation. Until now, neither observations nor
    one-dimensional analytical convection models could put constraints on
    granulation in red giants. With asteroseismology, this study can now be
    performed. We analyze \~{}1000 red giants that have been observed by Kepler
    during 13 months. We fit the power spectra with Harvey-like profiles to
    retrieve the characteristics of the granulation (timescale
    {$\tau$}$_{gran}$ and power P $_{gran}$). We search for a
    correlation between these parameters and the global acoustic-mode
    parameter (the position of maximum power, {$\nu$}$_{max}$) as well as
    with stellar parameters (mass, radius, surface gravity (log g), and
    effective temperature (T $_{eff}$)). We show that
    {$\tau$}$_{eff}$vprop{$\nu$}$^{-0.89}$ $_{max}$ and P
    $_{gran}$vprop{$\nu$}$^{-1.90}$ $_{max}$, which is
    consistent with the theoretical predictions. We find that the
    granulation timescales of stars that belong to the red clump have
    similar values while the timescales of stars in the red giant branch are
    spread in a wider range. Finally, we show that realistic
    three-dimensional simulations of the surface convection in stars,
    spanning the (T $_{eff}$, log g) range of our sample of red
    giants, match the Kepler observations well in terms of trends.
    }",
    doi = {10.1088/0004-637X/741/2/119},
    adsurl = {http://adsabs.harvard.edu/abs/2011ApJ...741..119M},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Hekker}, S., Y. {Elsworth}, J. {De Ridder}, B. {Mosser}, R. ~A. {Garcia}, T. {Kallinger}, S. {Mathur}, D. {Huber}, D. ~L. {Buzasi}, H. ~L. {Preston}, S. ~J. {Hale}, J. {Ballot}, W. ~J. {Chaplin}, C. {Regulo}, T. ~R. {Bedding}, D. {Stello}, W. ~J. {Borucki}, D. ~G. {Koch}, J. {Jenkins}, C. {Allen}, R. ~L. {Gilliland}, H. {Kjeldsen}, and J. {Christensen-Dalsgaard}. 2011. VizieR Online Data Catalog: Solar-like oscillations in Kepler red giants (Hekker+, 2011). Vizier online data catalog 352 59131.
    [BibTeX] [Abstract]

    {For this investigation we use Kepler data obtained during the first four months of operation. These data have been analysed by different groups using already published methods and the results are compared. We also performed simulations to investigate the uncertainty on the resulting parameters due to different realizations of the stochastic signal. (1 data file). }

    @ARTICLE{2011yCat..35259131H,
    author = {{Hekker}, S. and {Elsworth}, Y. and {De Ridder}, J. and {Mosser}, B. and
    {Garcia}, R.~A. and {Kallinger}, T. and {Mathur}, S. and {Huber}, D. and
    {Buzasi}, D.~L. and {Preston}, H.~L. and {Hale}, S.~J. and {Ballot}, J. and
    {Chaplin}, W.~J. and {Regulo}, C. and {Bedding}, T.~R. and {Stello}, D. and
    {Borucki}, W.~J. and {Koch}, D.~G. and {Jenkins}, J. and {Allen}, C. and
    {Gilliland}, R.~L. and {Kjeldsen}, H. and {Christensen-Dalsgaard}, J.
    },
    title = "{VizieR Online Data Catalog: Solar-like oscillations in Kepler red giants (Hekker+, 2011)}",
    journal = {VizieR Online Data Catalog},
    keywords = {Stars: giant, Stars: late-type, Photometry},
    year = 2011,
    month = may,
    volume = 352,
    pages = {59131},
    abstract = "{For this investigation we use Kepler data obtained during the first four
    months of operation. These data have been analysed by different groups
    using already published methods and the results are compared. We also
    performed simulations to investigate the uncertainty on the resulting
    parameters due to different realizations of the stochastic signal.
    (1 data file).
    }",
    adsurl = {http://adsabs.harvard.edu/abs/2011yCat..35259131H},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Mathur}, S., R. {Handberg}, T. ~L. {Campante}, R. ~A. {García}, T. {Appourchaux}, T. ~R. {Bedding}, B. {Mosser}, W. ~J. {Chaplin}, J. {Ballot}, O. {Benomar}, A. {Bonanno}, E. {Corsaro}, P. {Gaulme}, S. {Hekker}, C. {Régulo}, D. {Salabert}, G. {Verner}, T. ~R. {White}, I. ~M. {Brandão}, O. ~L. {Creevey}, G. {Do{v g}an}, Y. {Elsworth}, D. {Huber}, S. ~J. {Hale}, G. {Houdek}, C. {Karoff}, T. ~S. {Metcalfe}, J. {Molenda-Żakowicz}, M. ~J. ~P. ~F. ~G. {Monteiro}, M. ~J. {Thompson}, J. {Christensen-Dalsgaard}, R. ~L. {Gilliland}, S. ~D. {Kawaler}, H. {Kjeldsen}, E. ~V. {Quintana}, D. ~T. {Sanderfer}, and S. ~E. {Seader}. 2011. Solar-like Oscillations in KIC 11395018 and KIC 11234888 from 8 Months of Kepler Data. \apj 733 95. doi:10.1088/0004-637X/733/2/95
    [BibTeX] [Abstract]

    {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. }

    @ARTICLE{2011ApJ...733...95M,
    author = {{Mathur}, S. and {Handberg}, R. and {Campante}, T.~L. and {Garc{\'{\i}}a}, R.~A. and
    {Appourchaux}, T. and {Bedding}, T.~R. and {Mosser}, B. and
    {Chaplin}, W.~J. and {Ballot}, J. and {Benomar}, O. and {Bonanno}, A. and
    {Corsaro}, E. and {Gaulme}, P. and {Hekker}, S. and {R{\'e}gulo}, C. and
    {Salabert}, D. and {Verner}, G. and {White}, T.~R. and {Brand{\~a}o}, I.~M. and
    {Creevey}, O.~L. and {Do{\v g}an}, G. and {Elsworth}, Y. and
    {Huber}, D. and {Hale}, S.~J. and {Houdek}, G. and {Karoff}, C. and
    {Metcalfe}, T.~S. and {Molenda-{\.Z}akowicz}, J. and {Monteiro}, M.~J.~P.~F.~G. and
    {Thompson}, M.~J. and {Christensen-Dalsgaard}, J. and {Gilliland}, R.~L. and
    {Kawaler}, S.~D. and {Kjeldsen}, H. and {Quintana}, E.~V. and
    {Sanderfer}, D.~T. and {Seader}, S.~E.},
    title = "{Solar-like Oscillations in KIC 11395018 and KIC 11234888 from 8 Months of Kepler Data}",
    journal = {\apj},
    archivePrefix = "arXiv",
    eprint = {1103.4085},
    primaryClass = "astro-ph.SR",
    keywords = {asteroseismology, methods: data analysis, stars: individual: KIC 11395018 KIC 11234888, stars: oscillations, stars: solar-type},
    year = 2011,
    month = jun,
    volume = 733,
    eid = {95},
    pages = {95},
    abstract = "{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.
    }",
    doi = {10.1088/0004-637X/733/2/95},
    adsurl = {http://adsabs.harvard.edu/abs/2011ApJ...733...95M},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Huber}, D., T. ~R. {Bedding}, D. {Stello}, B. {Mosser}, S. {Mathur}, T. {Kallinger}, S. {Hekker}, Y. ~P. {Elsworth}, D. ~L. {Buzasi}, J. {De Ridder}, R. ~L. {Gilliland}, H. {Kjeldsen}, W. ~J. {Chaplin}, R. ~A. {García}, S. ~J. {Hale}, H. ~L. {Preston}, T. ~R. {White}, W. ~J. {Borucki}, J. {Christensen-Dalsgaard}, B. ~D. {Clarke}, J. ~M. {Jenkins}, and D. {Koch}. 2010. Asteroseismology of Red Giants from the First Four Months of Kepler Data: Global Oscillation Parameters for 800 Stars. \apj 723 1607-1617. doi:10.1088/0004-637X/723/2/1607
    [BibTeX] [Abstract]

    {We have studied solar-like oscillations in \~{}800 red giant stars using Kepler long-cadence photometry. The sample includes stars ranging in evolution from the lower part of the red giant branch to the helium main sequence. We investigate the relation between the large frequency separation ({$\Delta$}{$\nu$}) and the frequency of maximum power ({$\nu$}$_{max}$) and show that it is different for red giants than for main-sequence stars, which is consistent with evolutionary models and scaling relations. The distributions of {$\nu$}$_{max}$ and {$\Delta$}{$\nu$} are in qualitative agreement with a simple stellar population model of the Kepler field, including the first evidence for a secondary clump population characterized by M {\gt}\~{} 2 M $_{sun}$ and {$\nu$}$_{max}$ \~{}= 40-110 {$\mu$}Hz. We measured the small frequency separations {$\delta$}{$\nu$}$_{02}$ and {$\delta$}{$\nu$}$_{01}$ in over 400 stars and {$\delta$}{$\nu$}$_{03}$ in over 40. We present C-D diagrams for l = 1, 2, and 3 and show that the frequency separation ratios {$\delta$}{$\nu$}$_{02}$/{$\Delta$}{$\nu$} and {$\delta$}{$\nu$}$_{01}$/{$\Delta$}{$\nu$} have opposite trends as a function of {$\Delta$}{$\nu$}. The data show a narrowing of the l = 1 ridge toward lower {$\nu$}$_{max}$, in agreement with models predicting more efficient mode trapping in stars with higher luminosity. We investigate the offset epsilon in the asymptotic relation and find a clear correlation with {$\Delta$}{$\nu$}, demonstrating that it is related to fundamental stellar parameters. Finally, we present the first amplitude-{$\nu$}$_{max}$ relation for Kepler red giants. We observe a lack of low-amplitude stars for {$\nu$}$_{max}$ {\gt}\~{} 110 {$\mu$}Hz and find that, for a given {$\nu$}$_{max}$ between 40 and 110 {$\mu$}Hz, stars with lower {$\Delta$}{$\nu$} (and consequently higher mass) tend to show lower amplitudes than stars with higher {$\Delta$}{$\nu$}. }

    @ARTICLE{2010ApJ...723.1607H,
    author = {{Huber}, D. and {Bedding}, T.~R. and {Stello}, D. and {Mosser}, B. and
    {Mathur}, S. and {Kallinger}, T. and {Hekker}, S. and {Elsworth}, Y.~P. and
    {Buzasi}, D.~L. and {De Ridder}, J. and {Gilliland}, R.~L. and
    {Kjeldsen}, H. and {Chaplin}, W.~J. and {Garc{\'{\i}}a}, R.~A. and
    {Hale}, S.~J. and {Preston}, H.~L. and {White}, T.~R. and {Borucki}, W.~J. and
    {Christensen-Dalsgaard}, J. and {Clarke}, B.~D. and {Jenkins}, J.~M. and
    {Koch}, D.},
    title = "{Asteroseismology of Red Giants from the First Four Months of Kepler Data: Global Oscillation Parameters for 800 Stars}",
    journal = {\apj},
    archivePrefix = "arXiv",
    eprint = {1010.4566},
    primaryClass = "astro-ph.SR",
    keywords = {stars: late-type, stars: oscillations},
    year = 2010,
    month = nov,
    volume = 723,
    pages = {1607-1617},
    abstract = "{We have studied solar-like oscillations in \~{}800 red giant stars using
    Kepler long-cadence photometry. The sample includes stars ranging in
    evolution from the lower part of the red giant branch to the helium main
    sequence. We investigate the relation between the large frequency
    separation ({$\Delta$}{$\nu$}) and the frequency of maximum power
    ({$\nu$}$_{max}$) and show that it is different for red giants than
    for main-sequence stars, which is consistent with evolutionary models
    and scaling relations. The distributions of {$\nu$}$_{max}$ and
    {$\Delta$}{$\nu$} are in qualitative agreement with a simple stellar
    population model of the Kepler field, including the first evidence for a
    secondary clump population characterized by M {\gt}\~{} 2 M $_{sun}$
    and {$\nu$}$_{max}$ \~{}= 40-110 {$\mu$}Hz. We measured the small frequency
    separations {$\delta$}{$\nu$}$_{02}$ and {$\delta$}{$\nu$}$_{01}$ in
    over 400 stars and {$\delta$}{$\nu$}$_{03}$ in over 40. We present C-D
    diagrams for l = 1, 2, and 3 and show that the frequency separation
    ratios {$\delta$}{$\nu$}$_{02}$/{$\Delta$}{$\nu$} and
    {$\delta$}{$\nu$}$_{01}$/{$\Delta$}{$\nu$} have opposite trends as a function
    of {$\Delta$}{$\nu$}. The data show a narrowing of the l = 1 ridge toward
    lower {$\nu$}$_{max}$, in agreement with models predicting more
    efficient mode trapping in stars with higher luminosity. We investigate
    the offset epsilon in the asymptotic relation and find a clear
    correlation with {$\Delta$}{$\nu$}, demonstrating that it is related to
    fundamental stellar parameters. Finally, we present the first
    amplitude-{$\nu$}$_{max}$ relation for Kepler red giants. We observe
    a lack of low-amplitude stars for {$\nu$}$_{max}$ {\gt}\~{} 110 {$\mu$}Hz
    and find that, for a given {$\nu$}$_{max}$ between 40 and 110 {$\mu$}Hz,
    stars with lower {$\Delta$}{$\nu$} (and consequently higher mass) tend to show
    lower amplitudes than stars with higher {$\Delta$}{$\nu$}.
    }",
    doi = {10.1088/0004-637X/723/2/1607},
    adsurl = {http://adsabs.harvard.edu/abs/2010ApJ...723.1607H},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Bedding}, T. ~R., 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}, and A. {Weiss}. 2010. Solar-like Oscillations in Low-luminosity Red Giants: First Results from Kepler. \apjl 713 L176-L181. doi:10.1088/2041-8205/713/2/L176
    [BibTeX] [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 ({$\nu$}$_{max}$ {\gt} 100 {$\mu$}Hz, L łt\~{} 30 L $_{sun}$) 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 {$\delta$}{$\nu$}$_{02}$ 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. }

    @ARTICLE{2010ApJ...713L.176B,
    author = {{Bedding}, T.~R. and {Huber}, D. and {Stello}, D. and {Elsworth}, Y.~P. and
    {Hekker}, S. and {Kallinger}, T. and {Mathur}, S. and {Mosser}, B. and
    {Preston}, H.~L. and {Ballot}, J. and {Barban}, C. and {Broomhall}, A.~M. and
    {Buzasi}, D.~L. and {Chaplin}, W.~J. and {Garc{\'{\i}}a}, R.~A. and
    {Gruberbauer}, M. and {Hale}, S.~J. and {De Ridder}, J. and
    {Frandsen}, S. and {Borucki}, W.~J. and {Brown}, T. and {Christensen-Dalsgaard}, J. and
    {Gilliland}, R.~L. and {Jenkins}, J.~M. and {Kjeldsen}, H. and
    {Koch}, D. and {Belkacem}, K. and {Bildsten}, L. and {Bruntt}, H. and
    {Campante}, T.~L. and {Deheuvels}, S. and {Derekas}, A. and
    {Dupret}, M.-A. and {Goupil}, M.-J. and {Hatzes}, A. and {Houdek}, G. and
    {Ireland}, M.~J. and {Jiang}, C. and {Karoff}, C. and {Kiss}, L.~L. and
    {Lebreton}, Y. and {Miglio}, A. and {Montalb{\'a}n}, J. and
    {Noels}, A. and {Roxburgh}, I.~W. and {Sangaralingam}, V. and
    {Stevens}, I.~R. and {Suran}, M.~D. and {Tarrant}, N.~J. and
    {Weiss}, A.},
    title = "{Solar-like Oscillations in Low-luminosity Red Giants: First Results from Kepler}",
    journal = {\apjl},
    archivePrefix = "arXiv",
    eprint = {1001.0229},
    primaryClass = "astro-ph.SR",
    keywords = {stars: oscillations},
    year = 2010,
    month = apr,
    volume = 713,
    pages = {L176-L181},
    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
    ({$\nu$}$_{max}$ {\gt} 100 {$\mu$}Hz, L {\lt}\~{} 30 L $_{sun}$) 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 {\'e}chelle 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.
    }",
    doi = {10.1088/2041-8205/713/2/L176},
    adsurl = {http://adsabs.harvard.edu/abs/2010ApJ...713L.176B},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Chaplin}, W. ~J., T. {Appourchaux}, Y. {Elsworth}, R. ~A. {García}, G. {Houdek}, C. {Karoff}, T. ~S. {Metcalfe}, J. {Molenda-Żakowicz}, M. ~J. ~P. ~F. ~G. {Monteiro}, M. ~J. {Thompson}, T. ~M. {Brown}, J. {Christensen-Dalsgaard}, R. ~L. {Gilliland}, H. {Kjeldsen}, W. ~J. {Borucki}, D. {Koch}, J. ~M. {Jenkins}, J. {Ballot}, S. {Basu}, M. {Bazot}, T. ~R. {Bedding}, O. {Benomar}, A. {Bonanno}, I. ~M. {Brandão}, H. {Bruntt}, T. ~L. {Campante}, O. ~L. {Creevey}, M. ~P. {Di Mauro}, G. {Do{v g}an}, S. {Dreizler}, P. {Eggenberger}, L. {Esch}, S. ~T. {Fletcher}, S. {Frandsen}, N. {Gai}, P. {Gaulme}, R. {Handberg}, S. {Hekker}, R. {Howe}, D. {Huber}, S. ~G. {Korzennik}, J. ~C. {Lebrun}, S. {Leccia}, M. {Martic}, S. {Mathur}, B. {Mosser}, R. {New}, P. -O. {Quirion}, C. {Régulo}, I. ~W. {Roxburgh}, D. {Salabert}, J. {Schou}, S. ~G. {Sousa}, D. {Stello}, G. ~A. {Verner}, T. {Arentoft}, C. {Barban}, K. {Belkacem}, S. {Benatti}, K. {Biazzo}, P. {Boumier}, P. ~A. {Bradley}, A. -M. {Broomhall}, D. ~L. {Buzasi}, R. ~U. {Claudi}, M. ~S. {Cunha}, F. {D’Antona}, S. {Deheuvels}, A. {Derekas}, A. {García Hernández}, M. ~S. {Giampapa}, M. ~J. {Goupil}, M. {Gruberbauer}, J. ~A. {Guzik}, S. ~J. {Hale}, M. ~J. {Ireland}, L. ~L. {Kiss}, I. ~N. {Kitiashvili}, K. {Kolenberg}, H. {Korhonen}, A. ~G. {Kosovichev}, F. {Kupka}, Y. {Lebreton}, B. {Leroy}, H. -G. {Ludwig}, S. {Mathis}, E. {Michel}, A. {Miglio}, J. {Montalbán}, A. {Moya}, A. {Noels}, R. ~W. {Noyes}, P. ~L. {Pallé}, L. {Piau}, H. ~L. {Preston}, T. {Roca Cortés}, M. {Roth}, K. ~H. {Sato}, J. {Schmitt}, A. ~M. {Serenelli}, V. {Silva Aguirre}, I. ~R. {Stevens}, J. ~C. {Suárez}, M. ~D. {Suran}, R. {Trampedach}, S. {Turck-Chièze}, K. {Uytterhoeven}, R. {Ventura}, and P. ~A. {Wilson}. 2010. The Asteroseismic Potential of Kepler: First Results for Solar-Type Stars. \apjl 713 L169-L175. doi:10.1088/2041-8205/713/2/L169
    [BibTeX] [Abstract]

    {We present preliminary asteroseismic results from Kepler on three G-type stars. The observations, made at one-minute cadence during the first 33.5 days of science operations, reveal high signal-to-noise solar-like oscillation spectra in all three stars: about 20 modes of oscillation may be clearly distinguished in each star. We discuss the appearance of the oscillation spectra, use the frequencies and frequency separations to provide first results on the radii, masses, and ages of the stars, and comment in the light of these results on prospects for inference on other solar-type stars that Kepler will observe. }

    @ARTICLE{2010ApJ...713L.169C,
    author = {{Chaplin}, W.~J. and {Appourchaux}, T. and {Elsworth}, Y. and
    {Garc{\'{\i}}a}, R.~A. and {Houdek}, G. and {Karoff}, C. and
    {Metcalfe}, T.~S. and {Molenda-{\.Z}akowicz}, J. and {Monteiro}, M.~J.~P.~F.~G. and
    {Thompson}, M.~J. and {Brown}, T.~M. and {Christensen-Dalsgaard}, J. and
    {Gilliland}, R.~L. and {Kjeldsen}, H. and {Borucki}, W.~J. and
    {Koch}, D. and {Jenkins}, J.~M. and {Ballot}, J. and {Basu}, S. and
    {Bazot}, M. and {Bedding}, T.~R. and {Benomar}, O. and {Bonanno}, A. and
    {Brand{\~a}o}, I.~M. and {Bruntt}, H. and {Campante}, T.~L. and
    {Creevey}, O.~L. and {Di Mauro}, M.~P. and {Do{\v g}an}, G. and
    {Dreizler}, S. and {Eggenberger}, P. and {Esch}, L. and {Fletcher}, S.~T. and
    {Frandsen}, S. and {Gai}, N. and {Gaulme}, P. and {Handberg}, R. and
    {Hekker}, S. and {Howe}, R. and {Huber}, D. and {Korzennik}, S.~G. and
    {Lebrun}, J.~C. and {Leccia}, S. and {Martic}, M. and {Mathur}, S. and
    {Mosser}, B. and {New}, R. and {Quirion}, P.-O. and {R{\'e}gulo}, C. and
    {Roxburgh}, I.~W. and {Salabert}, D. and {Schou}, J. and {Sousa}, S.~G. and
    {Stello}, D. and {Verner}, G.~A. and {Arentoft}, T. and {Barban}, C. and
    {Belkacem}, K. and {Benatti}, S. and {Biazzo}, K. and {Boumier}, P. and
    {Bradley}, P.~A. and {Broomhall}, A.-M. and {Buzasi}, D.~L. and
    {Claudi}, R.~U. and {Cunha}, M.~S. and {D'Antona}, F. and {Deheuvels}, S. and
    {Derekas}, A. and {Garc{\'{\i}}a Hern{\'a}ndez}, A. and {Giampapa}, M.~S. and
    {Goupil}, M.~J. and {Gruberbauer}, M. and {Guzik}, J.~A. and
    {Hale}, S.~J. and {Ireland}, M.~J. and {Kiss}, L.~L. and {Kitiashvili}, I.~N. and
    {Kolenberg}, K. and {Korhonen}, H. and {Kosovichev}, A.~G. and
    {Kupka}, F. and {Lebreton}, Y. and {Leroy}, B. and {Ludwig}, H.-G. and
    {Mathis}, S. and {Michel}, E. and {Miglio}, A. and {Montalb{\'a}n}, J. and
    {Moya}, A. and {Noels}, A. and {Noyes}, R.~W. and {Pall{\'e}}, P.~L. and
    {Piau}, L. and {Preston}, H.~L. and {Roca Cort{\'e}s}, T. and
    {Roth}, M. and {Sato}, K.~H. and {Schmitt}, J. and {Serenelli}, A.~M. and
    {Silva Aguirre}, V. and {Stevens}, I.~R. and {Su{\'a}rez}, J.~C. and
    {Suran}, M.~D. and {Trampedach}, R. and {Turck-Chi{\`e}ze}, S. and
    {Uytterhoeven}, K. and {Ventura}, R. and {Wilson}, P.~A.},
    title = "{The Asteroseismic Potential of Kepler: First Results for Solar-Type Stars}",
    journal = {\apjl},
    archivePrefix = "arXiv",
    eprint = {1001.0506},
    primaryClass = "astro-ph.SR",
    keywords = {stars: interiors, stars: late-type, stars: oscillations},
    year = 2010,
    month = apr,
    volume = 713,
    pages = {L169-L175},
    abstract = "{We present preliminary asteroseismic results from Kepler on three G-type
    stars. The observations, made at one-minute cadence during the first
    33.5 days of science operations, reveal high signal-to-noise solar-like
    oscillation spectra in all three stars: about 20 modes of oscillation
    may be clearly distinguished in each star. We discuss the appearance of
    the oscillation spectra, use the frequencies and frequency separations
    to provide first results on the radii, masses, and ages of the stars,
    and comment in the light of these results on prospects for inference on
    other solar-type stars that Kepler will observe.
    }",
    doi = {10.1088/2041-8205/713/2/L169},
    adsurl = {http://adsabs.harvard.edu/abs/2010ApJ...713L.169C},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Allison}, J., I. {Barnes}, A. -M. {Broomhall}, W. {Chaplin}, G. {Davies}, Y. {Elsworth}, S. {Hale}, B. {Jackson}, B. {Miller}, R. {New}, and S. {Fletcher}. 2009. BiSON Update. Paper read at Solar-stellar dynamos as revealed by helio- and asteroseismology: gong 2008/soho 21.
    [BibTeX] [Abstract]

    {We present an update on the operation of the Birmingham Solar Oscillations Network (BiSON) network including our various running statistics such as duty cycle. We also give an update regarding our status and briefly outline the foreseeable future of the network. }

    @INPROCEEDINGS{2009ASPC..416..227A,
    author = {{Allison}, J. and {Barnes}, I. and {Broomhall}, A.-M. and {Chaplin}, W. and
    {Davies}, G. and {Elsworth}, Y. and {Hale}, S. and {Jackson}, B. and
    {Miller}, B. and {New}, R. and {Fletcher}, S.},
    title = "{BiSON Update}",
    booktitle = {Solar-Stellar Dynamos as Revealed by Helio- and Asteroseismology: GONG 2008/SOHO 21},
    year = 2009,
    series = {Astronomical Society of the Pacific Conference Series},
    volume = 416,
    editor = {{Dikpati}, M. and {Arentoft}, T. and {Gonz{\'a}lez Hern{\'a}ndez}, I. and
    {Lindsey}, C. and {Hill}, F.},
    month = dec,
    pages = {227},
    abstract = "{We present an update on the operation of the Birmingham Solar
    Oscillations Network (BiSON) network including our various running
    statistics such as duty cycle. We also give an update regarding our
    status and briefly outline the foreseeable future of the network.
    }",
    adsurl = {http://adsabs.harvard.edu/abs/2009ASPC..416..227A},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Broomhall}, A. -M., W. ~J. {Chaplin}, G. ~R. {Davies}, Y. {Elsworth}, S. ~T. {Fletcher}, S. ~J. {Hale}, B. {Miller}, and R. {New}. 2009. Definitive Sun-as-a-star p-mode frequencies: 23 years of BiSON observations. \mnras 396 L100-L104. doi:10.1111/j.1745-3933.2009.00672.x
    [BibTeX] [Abstract]

    {We present a list of `best possible’ estimates of low-degree p-mode frequencies from 8640 days of observations made by the Birmingham Solar-Oscillations Network (BiSON). This is the longest stretch of helioseismic data ever used for this purpose, giving exquisite precision in the estimated frequencies. Every effort has been made in the analysis to ensure that the frequency estimates are also accurate. In addition to presenting the raw best-fitting frequencies from our `peak-bagging’ analysis, we also provide tables of corrected frequencies pertinent to the quiet-Sun and an intermediate level of solar activity. }

    @ARTICLE{2009MNRAS.396L.100B,
    author = {{Broomhall}, A.-M. and {Chaplin}, W.~J. and {Davies}, G.~R. and
    {Elsworth}, Y. and {Fletcher}, S.~T. and {Hale}, S.~J. and {Miller}, B. and
    {New}, R.},
    title = "{Definitive Sun-as-a-star p-mode frequencies: 23 years of BiSON observations}",
    journal = {\mnras},
    archivePrefix = "arXiv",
    eprint = {0903.5219},
    primaryClass = "astro-ph.SR",
    keywords = {methods: data analysis, Sun: oscillations},
    year = 2009,
    month = jun,
    volume = 396,
    pages = {L100-L104},
    abstract = "{We present a list of `best possible' estimates of low-degree p-mode
    frequencies from 8640 days of observations made by the Birmingham
    Solar-Oscillations Network (BiSON). This is the longest stretch of
    helioseismic data ever used for this purpose, giving exquisite precision
    in the estimated frequencies. Every effort has been made in the analysis
    to ensure that the frequency estimates are also accurate. In addition to
    presenting the raw best-fitting frequencies from our `peak-bagging'
    analysis, we also provide tables of corrected frequencies pertinent to
    the quiet-Sun and an intermediate level of solar activity.
    }",
    doi = {10.1111/j.1745-3933.2009.00672.x},
    adsurl = {http://adsabs.harvard.edu/abs/2009MNRAS.396L.100B},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Chaplin}, W. ~J., Y. {Elsworth}, S. ~J. {Hale}, B. ~A. {Miller}, G. ~A. {Verner}, and R. {New}. 2006. The seismic Sun over three activity cycles. Paper read at Proceedings of soho 18/gong 2006/helas i, beyond the spherical sun.
    [BibTeX]
    @INPROCEEDINGS{2006ESASP.624E...8C,
    author = {{Chaplin}, W.~J. and {Elsworth}, Y. and {Hale}, S.~J. and {Miller}, B.~A. and
    {Verner}, G.~A. and {New}, R.},
    title = "{The seismic Sun over three activity cycles}",
    booktitle = {Proceedings of SOHO 18/GONG 2006/HELAS I, Beyond the spherical Sun},
    year = 2006,
    series = {ESA Special Publication},
    volume = 624,
    month = oct,
    eid = {8},
    pages = {8},
    adsurl = {http://adsabs.harvard.edu/abs/2006ESASP.624E...8C},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Allison}, J., I. {Barnes}, W. ~J. {Chaplin}, Y. ~P. {Elsworth}, S. ~J. {Hale}, B. {Jackson}, B. ~A. {Miller}, G. ~A. {Verner}, and R. {New}. 2006. BiSON update. Paper read at Proceedings of soho 18/gong 2006/helas i, beyond the spherical sun.
    [BibTeX]
    @INPROCEEDINGS{2006ESASP.624E..99A,
    author = {{Allison}, J. and {Barnes}, I. and {Chaplin}, W.~J. and {Elsworth}, Y.~P. and
    {Hale}, S.~J. and {Jackson}, B. and {Miller}, B.~A. and {Verner}, G.~A. and
    {New}, R.},
    title = "{BiSON update}",
    booktitle = {Proceedings of SOHO 18/GONG 2006/HELAS I, Beyond the spherical Sun},
    year = 2006,
    series = {ESA Special Publication},
    volume = 624,
    month = oct,
    eid = {99},
    pages = {99},
    adsurl = {http://adsabs.harvard.edu/abs/2006ESASP.624E..99A},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }

  • {Miller}, B. ~A., S. ~J. {Hale}, Y. {Elsworth}, W. ~J. {Chaplin}, G. ~R. {Isaak}, and R. {New}. 2004. Twenty-Eight Years of BISON Data. Paper read at Soho 14 helio- and asteroseismology: towards a golden future.
    [BibTeX]
    @INPROCEEDINGS{2004ESASP.559..571M,
    author = {{Miller}, B.~A. and {Hale}, S.~J. and {Elsworth}, Y. and {Chaplin}, W.~J. and
    {Isaak}, G.~R. and {New}, R.},
    title = "{Twenty-Eight Years of BISON Data}",
    booktitle = {SOHO 14 Helio- and Asteroseismology: Towards a Golden Future},
    year = 2004,
    series = {ESA Special Publication},
    volume = 559,
    editor = {{Danesy}, D.},
    month = oct,
    pages = {571},
    adsurl = {http://adsabs.harvard.edu/abs/2004ESASP.559..571M},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }