RADIUS DETERMINATION OF SOLAR-TYPE STARS USING ASTEROSEISMOLOGY: WHAT TO EXPECT FROM THE KEPLER MISSION

• Tipo: Artigo em Revista Científica Internacional
• Data: 2009

Autores

Dennis Stello (Autor) Outra; William J Chaplin (Autor) Outra; Hans Bruntt (Autor) Outra; Orlagh L Creevey (Autor) Outra; Antonio Garcia Hernandez (Autor) Outra; Mario J P F G Monteiro (Autor) FCUP; Andres Moya (Autor) Outra; Pierre Olivier Quirion (Autor) Outra; Sergio G Sousa (Autor) FCUP; Juan Carlos Suarez (Autor) Outra; Thierry Appourchaux (Autor) Outra; Torben Arentoft (Autor) Outra; Jerome Ballot (Autor) Outra; Timothy R Bedding (Autor) Outra; Jorgen Christensen Dalsgaard (Autor) Outra; Yvonne Elsworth (Autor) Outra; Stephen T Fletcher (Autor) Outra; Rafael A Garcia (Autor) Outra; Guenter Houdek (Autor) Outra; Sebastian J Jimenez Reyes (Autor) Outra; Hans Kjeldsen (Autor) Outra; Roger New (Autor) Outra; Clara Regulo (Autor) Outra; David Salabert (Autor) Outra; Thierry Toutain (Autor) Outra

Revista

Título: Astrophysical Journal

Vol. 700

Páginas: 1589-1602

ISSN: 0004-637X

Editora: American Astronomical Society

Indexação

ISI Web of Knowledge - 133 Citações

Scopus - 140 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Física

CORDIS: Ciências Físicas > Astronomia > Astrofísica ; Ciências Físicas > Astronomia ; Ciências Físicas

Outras Informações

ID Authenticus: P-003-GW3

DOI: 10.1088/0004-637x/700/2/1589

Resumo (PT): 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#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 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 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.

Abstract (EN): 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#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 Teff, 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 Teff 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.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 14