RADIUS DETERMINATION OF SOLAR-TYPE STARS USING ASTEROSEISMOLOGY: WHAT TO EXPECT FROM THE KEPLER MISSION
- Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, Sydney, NSW 2006 (Australia)
- School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)
- Instituto de Astrofisica de Canarias, E-38200 La Laguna, Tenerife (Spain)
- Instituto de Astrofisica de Andalucia, CSIC, CP3004 Granada (Spain)
- Centro de Astrofisica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal)
- Danish AsteroSeismology Centre (DASC), Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C (Denmark)
- Institut d' Astrophysique Spatiale (IAS), UMR8617, Batiment 121, F-91405 Orsay Cedex (France)
- Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, Postfach 1317, 85741 Garching (Germany)
- Faculty of Arts, Computing, Engineering and Sciences, Sheffield Hallam University, Sheffield S1 1WB (United Kingdom)
- Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, CEA, IRFU, SAp, centre de Saclay, F-91191 Gif-sur-Yvette (France)
- Institute of Astronomy, University of Vienna, A-1180 Vienna (Austria)
For distant stars, as observed by the NASA Kepler satellite, parallax information is currently of fairly low quality and is not complete. This limits the precision with which the absolute sizes of the stars and their potential transiting planets can be determined by traditional methods. Asteroseismology will be used to aid the radius determination of stars observed during NASA's Kepler mission. We report on the recent asteroFLAG hare-and-hounds Exercise no. 2, where a group of 'hares' simulated data of F-K main-sequence stars that a group of 'hounds' sought to analyze, aimed at determining the stellar radii. We investigated stars in the range 9 < V < 15, both with and without parallaxes. We further test different uncertainties in T {sub eff}, and compare results with and without using asteroseismic constraints. Based on the asteroseismic large frequency spacing, obtained from simulations of 4 yr time series data from the Kepler mission, we demonstrate that the stellar radii can be correctly and precisely determined, when combined with traditional stellar parameters from the Kepler Input Catalogue. The radii found by the various methods used by each independent hound generally agree with the true values of the artificial stars to within 3%, when the large frequency spacing is used. This is 5-10 times better than the results where seismology is not applied. These results give strong confidence that radius estimation can be performed to better than 3% for solar-like stars using automatic pipeline reduction. Even when the stellar distance and luminosity are unknown we can obtain the same level of agreement. Given the uncertainties used for this exercise we find that the input log g and parallax do not help to constrain the radius, and that T {sub eff} and metallicity are the only parameters we need in addition to the large frequency spacing. It is the uncertainty in the metallicity that dominates the uncertainty in the radius.
- OSTI ID:
- 21313755
- Journal Information:
- Astrophysical Journal, Vol. 700, Issue 2; Other Information: DOI: 10.1088/0004-637X/700/2/1589; Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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