High-precision photometry by telescope defocussing - II. The transiting planetary system WASP-4
. (2009) High-precision photometry by telescope defocussing - II. The transiting planetary system WASP-4. Monthly Notices of the Royal Astronomical Society, Vol.399 (No.1). pp. 287-294. ISSN 0035-8711 Full text not available from this repository.
Official URL: http://dx.doi.org/10.1111/j.1365-2966.2009.15283.x
We present and analyse light Curves Of four transits of the Southern hemisphere extrasolar planetary system WASP-4, obtained with a telescope defocused so the radius of each point spread function was 17 arcsec (44 pixels). This approach minimizes both random and systematic errors, allowing us to achieve scatters of between 0.60 and 0.88 mmag per observation over complete transit events. The light curves are augmented by published observations and analysed using the JKTEBOP code. The results of this process are combined with theoretical stellar model predictions to derive the physical properties of the WASP-4 system. We find that the mass and radius of the planet are M-b = 1.289(-0.090-0.000)(+0.090+0.039) M-Jup and R-b = 1.371(-0.035-0.000)(+0.032+0.021) R-Jup, respectively (statistical and systematic uncertainties). These quantities give a surface gravity and density of g(b) = 17.03(-0.54)(+0.97) ms(-2) and rho(b) = 0.500(-0.021-0.008)(+0.032+0.000) rho(Jup), and fit the trends for short-period extrasolar planets to have relatively high masses and surface, gravities. WASP-4 is now one of the best-quantified transitin extrasolar planetary systems, and significant further progress requires improvements to our understanding of the physical properties of low-mass stars.
|Item Type:||Journal Article|
|Subjects:||Q Science > QB Astronomy|
|Divisions:||Faculty of Science > Physics|
|Journal or Publication Title:||Monthly Notices of the Royal Astronomical Society|
|Date:||11 October 2009|
|Number of Pages:||8|
|Page Range:||pp. 287-294|
|Access rights to Published version:||Restricted or Subscription Access|
|Funder:||STFC, Northern Ireland Department of Culture, Arts and Leisure (DCAL), Communaute francaise de Belgique, Actions de recherche concertees, Academie Wallonie-Europe, NASA Astrophysics Data|
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