Entity

Time filter

Source Type


Karoff C.,University of Birmingham | Karoff C.,University of Aarhus | Chaplin W.J.,University of Birmingham | Appourchaux T.,CNRS Paris Institute of Astrophysics | And 51 more authors.
Astronomische Nachrichten | Year: 2010

We report on the first asteroseismic analysis of solar-type stars observed by Kepler. Observations of three G-type stars, 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 can clearly be distinguished in each star. We discuss the appearance of the oscillation spectra, including the presence of a possible signature of faculae, and the presence of mixed modes in one of the three stars (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Hinz P.,University of Arizona | Arbo P.,University of Arizona | Bailey V.,University of Arizona | Connors T.,University of Arizona | And 14 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

We report the first phased images using adaptive optics correction from the Large Binocular Telescope Interferometer. LBTI achieved first fringes in late 2010, with seeing-limited operation. Initial tests verified the feasibility of the setup and allowed us tócharacterize the phase variations from both the atmosphere and mechanical vibrations. Integration of the secondary-base AO systems was carried out in spring 2011 and spring 2012 for the right and left side respectively. Single aperture, diffraction-limited, operation has been commissioned and is used as a productive mode of the LBTI with the LMIRCam subsystem. We describe the initial observation for dual aperture observations and coherent imaging results. © 2012 SPIE. Source


Metcalfe T.S.,High Altitude Observatory | Monteiro M.J.P.F.G.,University of Porto | Thompson M.J.,High Altitude Observatory | Thompson M.J.,University of Sheffield | And 62 more authors.
Astrophysical Journal | Year: 2010

The primary science goal of the Kepler Mission is to provide a census of exoplanets in the solar neighborhood, including the identification and characterization of habitable Earth-like planets. The asteroseismic capabilities of the mission are being used to determine precise radii and ages for the target stars from their solar-like oscillations. Chaplin et al. published observations of three bright G-type stars, which were monitored during the first 33.5 days of science operations. One of these stars, the subgiant KIC 11026764, exhibits a characteristic pattern of oscillation frequencies suggesting that it has evolved significantly. We have derived asteroseismic estimates of the properties of KIC 11026764 from Kepler photometry combined with ground-based spectroscopic data. We present the results of detailed modeling for this star, employing a variety of independent codes and analyses that attempt to match the asteroseismic and spectroscopic constraints simultaneously. We determine both the radius and the age of KIC 11026764 with a precision near 1%, and an accuracy near 2% for the radius and 15% for the age. Continued observations of this star promise to reveal additional oscillation frequencies that will further improve the determination of its fundamental properties. © 2010. The American Astronomical Society. Source


Stello D.,University of Sydney | Basu S.,Yale University | Bruntt H.,French National Center for Scientific Research | Mosser B.,French National Center for Scientific Research | And 49 more authors.
Astrophysical Journal Letters | Year: 2010

Asteroseismology of stars in clusters has been a long-sought goal because the assumption of a common age, distance, and initial chemical composition allows strong tests of the theory of stellar evolution. We report results from the first 34days of science data from the Kepler Mission for the open cluster NGC 6819 - one of the four clusters in the field of view. We obtain the first clear detections of solar-like oscillations in the cluster red giants and are able to measure the large frequency separation, Δν, and the frequency of maximum oscillation power, νmax. We find that the asteroseismic parameters allow us to test cluster membership of the stars, and even with the limited seismic data in hand, we can already identify four possible non-members despite their having a better than 80% membership probability from radial velocity measurements. We are also able to determine the oscillation amplitudes for stars that span about 2 orders of magnitude in luminosity and find good agreement with the prediction that oscillation amplitudes scale as the luminosity to the power of 0.7. These early results demonstrate the unique potential of asteroseismology of the stellar clusters observed by Kepler. © 2010. The American Astronomical Society. All rights reserved. Source


Chaplin W.J.,University of Birmingham | Appourchaux T.,CNRS Paris Institute of Astrophysics | Elsworth Y.,University of Birmingham | Garcia R.A.,University Paris Diderot | And 116 more authors.
Astrophysical Journal Letters | Year: 2010

We present preliminary asteroseismic results from Kepler on three G-type stars. The observations, made at one-minute cadence during the first 33.5days 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. © 2010. The American Astronomical Society. All rights reserved. Source

Discover hidden collaborations