The homogeneous study of transiting systems (HoSTS). I. The pilot study of WASP-13

We present the fundamental stellar and planetary properties of the transiting planetary system WASP-13 within the framework of the Homogeneous Study of Transiting Systems (HoSTS). HoSTS aims to derive the fundamental stellar (Teff, [Fe/H], M∗, R∗) and planetary (Mpl, Rpl, Teq) physical properties of known transiting planets using a consistent methodology and homogeneous high-quality data set. Four spectral analysis techniques are independently applied to a Keck+HIRES spectrum of WASP-13 considering two distinct cases: unconstrained parameters and constrained log g from transit light curves. We check the derived stellar temperature against that from a different temperature diagnostic based on an INT+IDS Hα spectrum. The four unconstrained analyses render results that are in good agreement, and provide an improvement of 50% in the precision of T eff, and of 85% in [Fe/H] with respect to the WASP-13 discovery paper. The planetary parameters are then derived via the Monte Carlo Markov Chain modeling of the radial velocity and light curves, in iteration with stellar evolutionary models to derive realistic uncertainties. WASP-13 (1.187 ± 0.065 M ☉; 1.574 ± 0.048 R ☉) hosts a Saturn-mass, transiting planet (0.500 ± 0.037 MJup; 1.407 ± 0.052 RJup), and is at the end of its main-sequence lifetime (4-5.5 Gyr). Our analysis of WASP-13 showcases that both a detailed stellar characterization and transit modeling are necessary to well determine the fundamental properties of planetary systems, which are paramount in identifying and determining empirical relationships between transiting planets and their hosts.

Citation

Gómez Maqueo Chew , Y , Faedi , F , Cargile , P , Doyle , A P , Ghezzi , L , Sousa , S , Barros , S C C , Hebb , L , Cunha , K , Schuler , S C , Smith , V V , Collier Cameron , A , Pollacco , D , Santos , N C , Smalley , B & Stassun , K G 2013 , ' The homogeneous study of transiting systems (HoSTS). I. The pilot study of WASP-13 ' , Astrophysical Journal , vol. 768 , no. 1 , 79 . https://doi.org/10.1088/0004-637X/768/1/79

Publication

Astrophysical Journal

Status

Peer reviewed

DOI

https://doi.org/10.1088/0004-637X/768/1/79

ISSN

0004-637X

Type

Journal article

Rights

Description

Y.G.M.C. acknowledges postdoctoral funding support from the Vanderbilt Office of the Provost, through the Vanderbilt Initiative in Data-intensive Astrophysics (VIDA) and through a grant from the Vanderbilt International Office in support of the Vanderbilt–Warwick Exoplanets Collaboration. L.H.H. and K.G.S. acknowledge National Science Foundation grant AST-1009810. P.A.C. and K.G.S. acknowledge National Science Foundation grant AST-1109612. This work was supported by the European Research Council/European Community under the FP7 through Starting Grant agreement number 239953. S.G.S. is supported by the grant SFRH/BPD/47611/2008 from FCT (Portugal). L.G. acknowledges financial support provided by the PAPDRJ CAPES/FAPERJ Fellowship. N.C.S. also acknowledges the support from Fundação para a Ciência e a Tecnologia (FCT) through program Ciência 2007 funded by FCT/MCTES (Portugal) and POPH/FSE (EC), and in the form of grant reference PTDC/CTE-AST/098528/2008. The INT is operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.