J/A+A/510/A21 Stellar Limb-Darkening Coefficients (Sing, 2010)
Stellar limb-darkening coefficients for CoRot and Kepler.
Sing D.K.
<Astron. Astrophys. 510, A21 (2010)>
=2010A&A...510A..21S 2010A&A...510A..21S
ADC_Keywords: Models, atmosphere ; Binaries, eclipsing ; Planets
Keywords: stars: atmospheres - planetary systems - binaries: eclipsing
Abstract:
Transiting exoplanets provide unparalleled access to the fundamental
parameters of both extrasolar planets and their host stars. We present
limb-darkening coefficients (LDCs) for the exoplanet hunting CoRot and
Kepler missions. The LDCs are calculated with ATLAS stellar
atmospheric model grids and span a wide range of Teff, logg, and
metallically [M/H]. Both CoRot and Kepler use wide nonstandard
photometric filters, and are producing a large inventory of high-
quality transiting lightcurves, sensitive to stellar limb darkening.
Comparing the stellar model limb darkening to results from the first
seven CoRot planets, we find better fits are found when two model
intensities at the limb are excluded in the coefficient calculations.
This calculation method can help to avoid a major deficiency present
at the limbs of the 1D stellar models.
Description:
These are calculations of limb-darkening coefficients used to describe
the intensity profiles of stars for the CoRot and Kepler exoplanet
missions.
The full version of the tables can be also be found at
http://vega.lpl.arizona.edu/~singd/ which also includes an IDL program
to read and interpolate the tables.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 96 7327 Limb-darkening coefficients for CoRoT
table2.dat 96 7327 Limb-darkening coefficients for Kepler
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See also:
J/A+A/363/1081 : Non-linear limb-darkening law for LTE models I (Claret 2000)
J/A+A/401/657 : Non-linear limb-darkening law for LTE models II (Claret 2003)
J/A+AS/114/247 : Limb-darkening coefficients for R I J H K (Claret+ 1995)
J/A+A/335/647 : Limb-darkening coefficients for ubvyUBVRIJHK (Claret 1998)
Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 5 I5 K Teff [3500,50000] Stellar effective temperature
7- 10 F4.2 [cm/s+2] logg [0,5] Stellar surface gravity
12- 16 F5.2 [Sun] M/H [-0.5,+1.0] Stellar metallicity (1)
18- 24 F7.4 --- u Linear limb-darkening coefficient (2)
26- 32 F7.4 --- a Quadratic limb-darkening coefficient (2)
34- 40 F7.4 --- b Quadratic limb-darkening coefficient (2)
42- 48 F7.4 --- c2 3 parameter limb-darkening coefficient (2)
50- 56 F7.4 --- c3 3 parameter limb-darkening coefficient (2)
58- 64 F7.4 --- c4 3 parameter limb-darkening coefficient (2)
66- 72 F7.4 --- a1 4 parameter limb-darkening coefficient (2)
74- 80 F7.4 --- a2 ? 4 parameter limb-darkening coefficient (2)
82- 88 F7.4 --- a3 ? 4 parameter limb-darkening coefficient (2)
90- 96 F7.4 --- a4 ? 4 parameter limb-darkening coefficient (2)
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Note (1): The metallicity is log[metal/H], in the interval [+1 to -0.5],
all with a turbulent velocity of 2km/s.
Note (2): The linear, quadratic, and 3 parameter non-linear laws are
calculated with the improved calculation method using 15-ATLAS angles
with the limb intensities excluded, while the 4 parameter non-linear
law was calculated with all 17 angles including those at the limb.
The limb-darkening coefficients are:
* u (linear):
I(µ)/I(1) = 1 - u*(1-µ)
* a, b (quadratic):
I(µ)/I(1) = 1 - a*(1-µ) - b*(1-µ)**2
* c2, c3, c4 (3 parameter non-linear):
I(µ)/I(1) = 1 - c2*(1-µ) - c3*(1-µ**1.5) - c4*(1-µ**2)
* a1, a2, a3, a4 (4 parameter non-linear):
I(µ)/I(1) = 1 - a1*(1-µ**0.5) - a2*(1-µ)
- a3*(1-µ**1.5) - a4*(1-µ**2)
where I(1) is the specific intensity at the center of the disk, u, a,
b, c2, c3, c4, a1, a2, a3, a4 are the corresponding limb-darkening
coefficients and µ=cos(θ), θ being the angle between
the line of sight and the emergent intensity.
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Acknowledgements:
David Kent Sing, sing(at)astro.ex.ac.uk
(End) David Sing [Exeter, UK], Patricia Vannier [CDS] 07-Jan-2010