High-precision photometry by telescope defocussing. I. The transiting planetary system WASP-5 - Astrophysics > Earth and Planetary AstrophysicsReport as inadecuate




High-precision photometry by telescope defocussing. I. The transiting planetary system WASP-5 - Astrophysics > Earth and Planetary Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: We present high-precision photometry of two transit events of the extrasolarplanetary system WASP-5, obtained with the Danish 1.54m telescope at ESO LaSilla. In order to minimise both random and flat-fielding errors, we defocussedthe telescope so its point spread function approximated an annulus of diameter40 pixels 16 arcsec. Data reduction was undertaken using standard aperturephotometry plus an algorithm for optimally combining the ensemble of comparisonstars. The resulting light curves have point-to-point scatters of 0.50 mmag forthe first transit and 0.59 mmag for the second. We construct detailed signal tonoise calculations for defocussed photometry, and apply them to ourobservations. We model the light curves with the JKTEBOP code and combine theresults with tabulated predictions from theoretical stellar evolutionary modelsto derive the physical properties of the WASP-5 system. We find that the planethas a mass of M b = 1.637 +- 0.075 +- 0.033 Mjup, a radius of R b = 1.171 +-0.056 +- 0.012 Rjup, a large surface gravity of g b = 29.6 +- 2.8 m-s2 and adensity of rho b = 1.02 +- 0.14 +- 0.01 rhojup statistical and systematicuncertainties. The planet-s high equilibrium temperature of T eq = 1732 +- 80K makes it a good candidate for detecting secondary eclipses.



Author: John Southworth, T. C. Hinse, U. G. Joergensen, M. Dominik, D. Ricci, M. J. Burgdorf, A. Hornstrup, P. J. Wheatley, T. Anguita, V

Source: https://arxiv.org/







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