Homogeneous studies of transiting extrasolar planets - III. Additional planets and stellar models

By J. Southworth. 2010

229 citations recorded by the source corpus.

I derive the physical properties of 30 transiting extrasolar planetary systems using a homogeneous analysis of published data. The light curves are modelled with the jktebop code, with special attention paid to the treatment of limb darkening, orbital eccentricity and error analysis. The light from some systems is contaminated by faint nearby stars, which if ignored will systematically bias the results. I show that it is not realistically possible to account for this using only transit light curves: light-curve solutions must be constrained by measurements of the amount of contaminating light. A contamination of 5 per cent is enough to make the measurement of a planetary radius 2 per cent too low. The physical properties of the 30 transiting systems are obtained by interpolating in tabulated predictions from theoretical stellar models to find the best match to the light-curve parameters and the measured stellar velocity amplitude, temperature and metal abundance. Statistical errors are propagated by a perturbation analysis which constructs complete error budgets for each output parameter. These error budgets are used to compile a list of systems which would benefit from additional photometric or spectroscopic measurements. The systematic errors arising from the inclusion of stellar models are assessed by using five independent sets of theoretical predictions for low-mass stars. This model dependence sets a lower limit on the accuracy of measurements of the physical properties of the systems, ranging from 1 per cent for the stellar mass to 0.6 per cent for the mass of the planet and 0.3 per cent for other quantities. The stellar density and the planetary surface gravity and equilibrium temperature are not affected by this model dependence. An external test on these systematic errors is performed by comparing the two discovery papers of the WASP-11/HAT-P-10 system: these two studies differ in their assessment of the ratio of the radii of the components and the effective temperature of the star. I find that the correlations of planetary surface gravity and mass with orbital period have significance levels of only 3.1σ and 2.3σ, respectively. The significance of the latter has not increased with the addition of new data since Paper II. The division of planets into two classes based on Safronov number is increasingly blurred. Most of the objects studied here would benefit from improved photometric and spectroscopic observations, as well as improvements in our understanding of low-mass stars and their effective temperature scale.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/614eb09546672db21efe72d82f7c288d81614e0e

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In Astronomy and Astrophysics

1. Jon Fortney
2. N. Madhusudhan
3. M. Marley
4. A. Showman
5. R. Freedman
6. D. Sing
7. V. Parmentier
8. H. Wakeford

Citations in the corpus

• A chemical model for the atmosphere of hot Jupiters (2012, background): “Properties of HD 189733b and HD 189733 come from Southworth (2008, 2010).”
• Transmission spectral properties of clouds for hot Jupiter exoplanets (2014, methodology): “Here we use the well-studied hot Jupiter HD 189733b as an example atmosphere with Rp= 1.138 RJ, R∗= 0.756 R , gp= 3.34 ms−2, and Te f f = 1350 K (Southworth 2010; Torres et al. 2008).”
• DISEQUILIBRIUM CARBON, OXYGEN, AND NITROGEN CHEMISTRY IN THE ATMOSPHERES OF HD 189733b AND HD 209458b (2011, methodology): “HD 189733b orbits its host star at a distance of ∼0.031 AU (e.g., Southworth 2010).”
• Homogeneous studies of transiting extrasolar planets – IV. Thirty systems with space-based light curves (2011, unknown): “I Paper III (Southworth 2010) I extended the number of systems to30 and the number of theoretical predictions used to five sets, improving both the statistical weight of the ensemble and the precision of the systematic errorbars.”
• PROBABILISTIC FORECASTING OF THE MASSES AND RADII OF OTHER WORLDS (2016, methodology): “For extrasolar planets, we used the TEPCat catalog4 of “wellstudied transiting planets,” curated by John Southworth (Southworth 2008, 2009, 2010, 2011, 2012).”
• ON THE ANOMALOUS RADII OF THE TRANSITING EXTRASOLAR PLANETS (2011, result): “This figure is startlingly at odds with the observed value, R = 1.38 ± 0.02RJup (Southworth 2010).”
• TAU-REX I: A NEXT GENERATION RETRIEVAL CODE FOR EXOPLANETARY ATMOSPHERES (2014, methodology): “We base the simulation on a HD209458b like planet/star system (Charbonneau et al. 2000; Southworth 2010) with temperature and bulk composition taken from Venot et al. (2014).”