On stellar limb darkening and exoplanetary transits
TLDR
In this article, the authors compare stellar limb-darkening coefficients evaluated from model atmospheres with those derived from photometry, and compare the results of light-curve analyses and new model-atmosphere results mediated by synthetic photometry for a small sample of stars.Abstract:
This paper examines how to compare stellar limb-darkening coefficients evaluated from model atmospheres with those derived from photometry. Different characterizations of a given model atmosphere can give quite different numerical results (even for a given limb-darkening ‘law’), while light-curve analyses yield limb-darkening coefficients that are dependent on system geometry, and that are not directly comparable to any model-atmosphere representation. These issues are examined in the context of exoplanetary transits, which offer significant advantages over traditional binary-star eclipsing systems in the study of stellar limb darkening. ‘Like for like’ comparisons between light-curve analyses and new model-atmosphere results, mediated by synthetic photometry, are conducted for a small sample of stars. Agreement between the resulting synthetic-photometry/atmosphere-model (SPAM) limb-darkening coefficients and empirical values ranges from very good to quite poor, even though the targets investigated show only a small dispersion in fundamental stellar parameters.read more
Citations
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Book
The Exoplanet Handbook
TL;DR: In this paper, the authors present an overview of the solar system and its evolution, including the formation and evolution of stars, asteroids, and free-floating planets, as well as their internal and external structures.
Journal ArticleDOI
New limb-darkening coefficients for Phoenix/1d model atmospheres - II. Calculations for 5000 K ≤ Teff ≤ 10 000 K Kepler, CoRot, Spitzer, uvby, UBVRIJHK, Sloan, and 2MASS photometric systems
TL;DR: In this paper, the authors presented new calculations of limb-darkening coefficients for the spherically symmetric phoenix models, which were computed by covering the transmission curves of Kepler, CoRoT and Spitzer space missions, as well as the passbands of the Stromgren, Johnson-Cousins, Sloan, and 2MASS.
The Exoplanet Handbook: Formation and evolution
TL;DR: An overview of the processes described in this chapter is as follows in this paper, where the authors start with star formation in molecular clouds, and then gravitationally accumulate their mantles of ice and/or gas.
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Limb darkening and exoplanets: testing stellar model atmospheres and identifying biases in transit parameters
TL;DR: In this paper, it was shown that if one uses the quadratic limb-darkening law to parametrize limb darkening, fixing and fitting the LDCs can lead to significant biases -up to 3% and 1% in R_p/R_*, respectively, which are important for several confirmed and candidate exoplanets.
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ldtk: Limb Darkening Toolkit
Hannu Parviainen,Suzanne Aigrain +1 more
TL;DR: In this article, the authors present a Python package LDTk that automates the calculation of custom stellar limb darkening (LD) profiles and model-specific LDC coefficients using the library of PHOENIX-generated specific intensity spectra.
References
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Journal ArticleDOI
Analytic Lightcurves for Planetary Transit Searches
Kaisey S. Mandel,Eric Agol +1 more
TL;DR: In this paper, exact analytic formulae for the eclipse of a star described by quadratic or nonlinear limb darkening are presented for the HST observations of HD 209458, showing that the ratio of the planetary to stellar radii is 0.1207+-0.0003.
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Analytic Light Curves for Planetary Transit Searches
Kaisey S. Mandel,Eric Agol +1 more
TL;DR: In this paper, the exact analytic formulae for the eclipse of a star described by quadratic or nonlinear limb darkening were presented, and the authors applied these results to the Hubble Space Telescope observations of HD 209458, showing that the ratio of the planetary to stellar radii is 0.1207 ± 0.0003.
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TL;DR: In this paper, a large set of solar twins, stars which are spectroscopically and photometrically identical to the Sun, were used to set the absolute zero point of the effective temperature scale to within few degrees.
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An absolutely calibrated effective temperature scale from the InfraRed Flux Method
TL;DR: In this paper, the authors used a large set of solar twins, stars which are spectroscopically and photometrically identical to the Sun, to set the absolute zero point of the effective temperature scale to within few degrees.
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Spectroscopic parameters for 451 stars in the HARPS GTO planet search program - Stellar [Fe/H] and the frequency of exo-Neptunes
S. G. Sousa,Nuno C. Santos,Michel Mayor,Stéphane Udry,Luca Casagrande,Garik Israelian,Francesco Pepe,Didier Queloz,Mário J. P. F. G. Monteiro +8 more
TL;DR: In this article, a catalogue of accurate stellar parameters for 451 stars that represent the HARPS Guaranteed Time Observations (GTO) "high precision" sample was presented, and a useful calibration for the effective temperature as a function of the index color B -V and [Fe/H was presented.