Browsing by Author "Gruberbauer, Michael"

Browsing by Author "Gruberbauer, Michael"

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    The asteroseismic potential of Kepler: first results for solar-type stars 
    Chaplin, W. J.; Appourchaux, T.; Elsworth, Y.; Garcia, R. A.; Houdek, G.; Karoff, C.; Metcalfe, T. S.; Molenda-Zackowicz, J.; Monteiro, M. J. P. F. G.; Thompson, M. J.; Gruberbauer, Michael (American Astronomical Society, 2010-04-20)
    We present preliminary asteroseismic results from Kepler on three G-type stars. The observations, made at one-minute cadence during the first 33.5 d of science operations, reveal high signal-to-noise solar-like oscillation ...

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    Asteroseismology of red giants from the first four months of Kepler data: fundamental stellar parameters 
    Gruberbauer, Michael; Kallinger, T.; Mosser, B.; Hekker, S.; Huber, D.; Stello, D.; Mathur, S.; Basu, S.; Bedding, T. R.; Chaplin, W. J. (EDP Sciences, 2010-10)
    Context. Clear power excess in a frequency range typical for solar-type oscillations in red giants has been detected in more than 1000 stars, which have been observed during the first 138 days of the science operation of ...

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    Bayesian asteroseismology 
    Gruberbauer, Michael (Halifax, N.S. : Saint Mary's University, 2013)
    This thesis presents a new probabilistic method for the asteroseismic analysis of stellar structure and evolution with the goal of providing a universal tool to improve our knowledge of stellar modelling. This new method ...

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    Bayesian asteroseismology of 23 solar-like Kepler targets 
    Gruberbauer, Michael; Guenther, David B.; MacLeod, K.; Kallinger, T. (Oxford University Press, 2013-10)
    We study 23 previously published Kepler targets to perform a consistent grid-based Bayesian asteroseismic analysis and compare our results to those obtained via the Asteroseismic Modelling Portal. We find differences in ...

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    Bayesian seismology of the Sun 
    Gruberbauer, Michael; Guenther, David B. (Oxford University PressRoyal Astronomical Society, 2013-04-12)
    We perform a Bayesian grid-based analysis of the solar l = 0, 1, 2 and 3 p modes obtained via BiSON in order to deliver the first Bayesian asteroseismic analysis of the solar composition problem. We do not find decisive ...

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    CINDERELLA: comparison of INDEpendent RELative least-squares amplitudes 
    Gruberbauer, Michael; Reegen, P.; Schneider, L.; Weiss, W. W. (EDP Sciences, 2008-06)
    Context. The identification of smaller and smaller signals from objects observed with a non-perfect instrument in a noisy environment poses a challenge for a statistically clean data analysis. Aims. We compute the probability ...

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    The connection between stellar granulation and oscillation as seen by the Kepler mission 
    Kallinger, T.; De Ridder, J.; Hekker, S.; Mathur, S.; Mosser, B.; Gruberbauer, Michael; Garcia, R. A.; Karoff, C.; Ballot, J. (EDP Sciences, 2014-10)
    Context. The long and almost continuous observations by Kepler show clear evidence of a granulation background signal in a large sample of stars, which is interpreted as the surface manifestation of convection. It has been ...

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    Detection of solar-like oscillations, observational constraints, and stellar models for theta Cyg, the brightest star observed by the Kepler Mission 
    Guzik, J. A.; Houdek, G; Chaplin, W. J.; Smalley, B.; Kurtz, W.; Gilliland, R. L.; Mullally, F.; Rowe, J. F.; Bryson, S. T.; Antoci, V.; Gruberbauer, Michael (The American Astronomical Society, 2016-11-01)
    [Theta] Cygni is an F3 spectral type magnitude V=4.48 main-sequence star that was the brightest star observed by the original Kepler spacecraft mission. Short-cadence (58.8 s) photometric data using a custom aperture were ...

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    Evolutionary influences on the structure of red-giant acoustic oscillation spectra from 600d of Kepler observations 
    Guenther, David B.; Gruberbauer, Michael; Kallinger, T.; Hekker, S.; Mosser, B.; De Ridder, J.; Bedding, T. R.; Elsworth, Y. P.; Stello, D.; Basu, S. (EDP Sciences, 2012-05)
    Context. It was recently discovered that the period spacings of mixed pressure/gravity dipole modes in red giants permit a distinction between the otherwise unknown evolutionary stage of these stars. The Kepler space mission ...

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    The first evidence for multiple pulsation axes: a new rapidly oscillating Ap star in the Kepler field, KIC 10195926 
    Gruberbauer, Michael; Kurtz, D. W.; Cunha, M. S.; Saio, H.; Bigot, L.; Balona, L. A.; Elkin, V. G.; Shibahashi, H.; Brandao, I. M.; Uytterhoeven, K. (Royal Astronomical Society, 2011-07-01)
    We have discovered a new rapidly oscillating Ap (roAp) star among the Kepler mission target stars, KIC 10195926. This star shows two pulsation modes with periods that are amongst the longest known for roAp stars at 17.1 ...

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    [gamma] Doradus pulsation in two pre-main sequence stars discovered by CoRoT 
    Zwintz, K.; Fossati, L.; Ryabchikova, T.; Kaiser, A.; Gruberbauer, Michael; Barnes, T. G.; Baglin, A.; Chaintreuil, S. (EDP Sciences, 2013-02)
    Context. Pulsations in pre-main sequence stars have been discovered several times within the last years. But nearly all of these pulsators are of [delta] Scuti-type. [gamma] Doradus-type pulsation in young stars has been ...

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    The Kepler characterization of the variability among A- and F-type stars 
    Uytterhoeven, K.; Moya, A.; Grigahcene, A.; Guzik, J. A.; Gutierrez-Soto, J.; Smalley, B.; Handler, G.; Balona, L. A.; Niemczura, E.; Fox Machado, L.; Gruberbauer, Michael (EDP Sciences, 2011-10)
    Context. The Kepler spacecraft is providing time series of photometric data with micromagnitude precision for hundreds of A-F type stars. Aims. We present a first general characterization of the pulsational behaviour of ...

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    Kepler observations of rapidly oscillating Ap, [delta] Scuti and [gamma] Doradus pulsations in Ap stars 
    Balona, L. A.; Cunha, M. S.; Kurtz, D. W.; Brandao, I. M.; Gruberbauer, Michael; Saio, H.; Ostensen, R.; Elkin, V. G.; Borucki, W. J.; Christensen-Dalsgaard, J. (Wiley-Blackwell, 2011-01-01)
    Observations of the A5p star KIC 8677585 obtained during the Kepler 10-d commissioning run with 1-min time resolution show that it is a rapidly oscillating Ap (roAp) star with several frequencies with periods near 10 min. ...

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    Modeling convective core overshoot and diffusion in Procyon constrained by asteroseismic data 
    Guenther, David B.; Demarque, P.; Gruberbauer, Michael (IOP Publishing Limited, 2014-06-01)
    We compare evolved stellar models, which match Procyon’s mass and position in the HR diagram, to current groundbased asteroseismic observations. Diffusion of helium and metals along with two conventional core overshoot ...

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    MOST observations of the roAp stars HD 9289, HD 99563, and HD 134214 
    Guenther, David B.; Gruberbauer, Michael; Huber, D.; Kuschnig, R.; Weiss, W. W.; Matthews, J. M.; Moffat, A. F. J.; Rowe, J. F.; Rucinski, S. M.; Sasselov, D. (EDP Sciences, 2011-06)
    We report on the analysis of high-precision space-based photometry of the roAp (rapidly oscillating Ap) stars HD 9289, HD 99563, and HD 134214. All three stars were observed by the MOST satellite for more than 25 days, ...

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    MOST photometry and modeling of the rapidly oscillating (roAp) star [gamma] Equulei 
    Guenther, David B.; Gruberbauer, Michael; Saio, H.; Huber, D.; Kallinger, T.; Weiss, W. W.; Kuschnig, R.; Matthews, J. M.; Moffat, A. F. J.; Rucinski, S. (EDP Sciences, 2008)
    Aims. Despite photometry and spectroscopy of its oscillations obtained over the past 25 years, the pulsation frequency spectrum of the rapidly oscillating Ap (roAp) star [gamma] Equ has remained poorly understood. Better ...

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    MOST photometry of the roAp star 10 Aquilae 
    Guenther, David B.; Huber, D.; Saio, H.; Gruberbauer, Michael; Weiss, W. W.; Rowe, J. F.; Hareter, M.; Kallinger, T.; Reegen, P.; Matthews, J. M. (EDP Sciences, 2008-05)
    Context. We present 31.2 days of nearly continuous MOST photometry of the rapidly oscillating Ap star 10 Aql. Aims. The goal was to provide an unambiguous frequency identification for this little studied star, as well as ...

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    MOST photometry of the RRd Lyrae variable AQ Leo: two radial modes, 32 combination frequencies and beyond 
    Guenther, David B.; Gruberbauer, Michael; Kolenberg, Katrien; Rowe, Jason F.; Huber, Daniel; Matthews, Jaymie M.; Reegen, Piet; Kuschnig, Rainer; Cameron, Chris; Kallinger, T. (Oxford University Press, 2007-08)
    Highly precise and nearly uninterrupted optical photometry of the RR Lyrae star AQ Leo was obtained with the MOST (Microvariability and Oscillations of Stars) satellite over 34.4 d in 2005 February–March. AQ Leo was the ...

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    The nature of p-modes and granulation in HD 49933 observed by CoRoT 
    Guenther, David B.; Gruberbauer, Michael; Kallinger, T.; Fossati, L.; Weiss, W. W. (EDP Sciences, 2010-02)
    Context. Recent observations of HD 49933 by the space-photometric mission CoRoT provide photometric evidence of solar type oscillations in a star other than our Sun. The first published reduction, analysis, and interpretation ...

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    The nature of p-modes and granulation in Procyon: new MOST photometry and new Yale convection models 
    Guenther, David B.; Kallinger, T.; Gruberbauer, Michael; Huber, D.; Weiss, W. W.; Kuschnig, R.; Demarque, P.; Robinson, F.; Matthews, J. M.; Moffat, A. F. J. (American Astronomical Society, 2008-11)
    We present new photometry of Procyon, obtained by MOST during a 38 day run in 2007, and frequency analyses of those data. The long time coverage and low point-to-point scatter of the light curve yield an average noise ...