J/A+A/539/A102 HD 209458 and HD 189733 theoretical spectra (Hayek+, 2012)
Limb darkening laws for two exoplanet host stars derived from 3D stellar model
atmospheres. Comparison with 1D models and HST light curve observations.
Hayek W., Sing D., Pont F., Asplund M.
<Astron. Astrophys. 539, A102 (2012)>
=2012A&A...539A.102H 2012A&A...539A.102H
ADC_Keywords: Stars, G-type ; Stars, K-type ; Planets ; Spectroscopy
Keywords: stars: atmospheres - stars: individual: HD 209458 -
stars: individual: HD 189733 -
planets and satellites: individual: HD 209458b
planets and satellites: individual: HD 189733b
Abstract:
We compare limb darkening laws derived from 3D hydrodynamical model
atmospheres and 1D hydrostatic MARCS models for the host stars of two
well-studied transiting exoplanet systems, the late-type dwarfs
HD 209458 and HD 189733. The surface brightness distribution of the
stellar disks is calculated for a wide spectral range using 3D LTE
spectrum formation and opacity sampling. We test our theoretical
predictions using least-squares fits of model light curves to
wavelength-integrated primary eclipses that were observed with the
Hubble Space Telescope (HST).
Description:
Theoretical spectrum computations for the G-type dwarf HD 209458 and
the K-type dwarf HD 189733 are presented, based on 3D hydrodynamical
models of the stellar atmospheres. Surface intensities were computed
in LTE using the SCATE spectrum formation code and cover the
wavelength region between about 910 Angstroem and 20 micron with
constant sampling of R=λ/δ_λ=20,000. The stellar
disk was sampled at the disk center (µ=cos(θ)=1.0) and at
angles µ = 0.90, 0.80, 0.70, 0.60, 0.50, 0.40, 0.30, 0.25, 0.20,
0.15, 0.125, 0.1, 0.075, 0.05, 0.025, 0.01 towards the limb. Use
integration weights 0.05, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.075, 0.05,
0.05, 0.0375, 0.025, 0.025, 0.025, 0.025, 0.02, 0.0125 to obtain
fluxes.
Objects:
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RA (2000) DE Designation(s)
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20 00 43.7 +22 42 39 HD 189733 = HD 189733
22 03 10.8 +18 53 04 HD 209458 = V* V376 Peg
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
hd189733.dat 34 1833535 HD 189733 intensities
hd209458.dat 34 1833535 HD 209458 intensities
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See also:
J/A+A/510/A21 : Stellar Limb-Darkening Coefficients (Sing, 2010)
J/A+A/526/A71 : C abundances in G and K nearby stars (Da Silva+, 2011)
J/A+A/529/A75 : Limb-darkening coefficients (Claret+, 2011)
Byte-by-byte Description of file: hd189733.dat hd209458.dat
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Bytes Format Units Label Explanations
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1- 5 F5.3 --- mu [0.01/1] µ angle (1)
7- 18 E12.6 0.1nm lambda Vacuum wavelength
23- 34 E12.6 10-2W/m2/nm/sr Int Specific intensity (in erg/cm2/s/Å/sr)
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Note (1): µ values are 0.010, 0.025, 0.075, 0.100, 0.125, 0.150, 0.200,
0.250, 0.300, 0.400, 0.500, 0.600, 0.7800, 0.800, 0.900 and 1.000.
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Acknowledgements:
Wolfgang Hayek, hayek(at)MPA-Garching.MPG.DE
(End) Wolfgang Hayek [MPA, Garching], Patricia Vannier [CDS] 03-Feb-2012