J/AJ/156/28 Properties for exoplanets with Spitzer light curves (Adams+, 2018)
Reassessing exoplanet light curves with a thermal model.
Adams A.D., Laughlin G.
<Astron. J., 156, 28-28 (2018)>
=2018AJ....156...28A 2018AJ....156...28A (SIMBAD/NED BibCode)
ADC_Keywords: Exoplanets ; Stars, masses ; Stars, diameters ;
Effective temperatures ; Binaries, orbits
Keywords: atmospheric effects - methods: data analysis - methods: numerical -
planets and satellites: atmospheres -
planets and satellites: gaseous planets - techniques: photometric
Abstract:
We present a uniform assessment of existing near-infrared Spitzer Space
Telescope observations of planet-bearing stars. Using a simple
four-parameter blackbody thermal model, we analyze stars for which
photometry in at least one of Spitzer's IRAC bands has been obtained
over either the entirety or a significant fraction of the planetary
orbit. Systems in this category comprise 10 well-studied systems with
hot Jupiters on circular or near-circular orbits (HAT-P-7, HD 149026,
HD 189733, HD 209458, WASP-12, WASP-14, WASP-18, WASP-19, WASP-33, and
WASP-43), as well as three stars harboring planets on significantly
eccentric orbits (GJ 436, HAT-P-2, and HD 80606). We find that our simple
model, in almost all cases, accurately reproduces the minimum and maximum
planetary emission, as well as the phase offsets of these extrema with
respect to transits/secondary eclipses. For one notable exception,
WASP-12 b, adding an additional parameter to account for its tidal
distortion is not sufficient to reproduce its photometric features.
Full-orbit photometry is available in multiple wavelengths for 10 planets.
We find that the returned parameter values for independent fits to each
band are largely in agreement. However, disagreements in nightside
temperature suggest distinct atmospheric layers, each with their own
characteristic minimum temperature. In addition, a diversity in albedos
suggests variation in the opacity of the photospheres. While previous
works have pointed out trends in photometric features based on system
properties, we cannot conclusively identify analogous trends for physical
model parameters. To make the connection between full-phase data and
physical models more robust, a higher signal-to-noise ratio must come
from both increased resolution and a careful treatment of instrumental
systematics.
Description:
For a selection of planets orbiting relatively bright parent stars,
photometry in near-infrared bands has been obtained throughout the orbit;
such data are referred to as light-curve observations. The Spitzer mission,
during both its cryogenic and "warm" phases, has obtained spectra, eclipse,
transit, or full-phase observations of over 100 planet-bearing stars
(Han et al. 2014PASP..126..827H 2014PASP..126..827H). Spitzer's IRAC detector (Werner et al.
2004ApJS..154....1W 2004ApJS..154....1W) has operated in four wavelength channels centered
at 3.6, 4.5, 5.8, and 8.0 µm. During the warm phase, only the 3.6 and
4.5 µm channels have been available. The infrared spectrograph
(Houck et al. 2004ApJS..154...18H 2004ApJS..154...18H) has provided spectra, as well as
photometry at 16 µm in the peak-up imaging mode, and the MIPS instrument
(Rieke et al. 2004ApJS..154...25R 2004ApJS..154...25R) provides photometry in the mid- to
far-infrared, particularly at 24 µm. However, all light curves analyzed
in this work (listed in Section 2.2) were reduced and rebinned from
data from the IRAC channels alone.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 146 12 Orbital and stellar properties for exoplanets
with Spitzer light curves
table2.dat 90 26 *Best-fit parameters from radiative model
table4.dat 233 77 Eclipse properties for exoplanets with Spitzer
light curves
table5.dat 264 40 Transit properties for exoplanets with Spitzer
light curves
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Note on table2.dat: The parameter values from our blackbody model returning
the most favorable likelihood from Markov chain Monte Carlo (MCMC) algorithms.
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See also:
J/AJ/133/1828 : Transit light curves of HD 189733 (Winn+, 2007)
J/ApJS/168/297 : Stellar parameters of nearby cool stars (Takeda+, 2007)
J/A+A/498/L5 : Photometry and spectroscopy of HD 80606b (Moutou+, 2009)
J/A+A/502/695 : Observations of HD 80606 planetary system (Pont+, 2009)
J/ApJ/707/167 : Transiting planetary system WASP-18 (Southworth+, 2009)
J/A+A/516/A95 : Photometry and spectroscopy of HD 80606b (Hebrard+, 2010)
J/A+A/526/L10 : Transits of WASP-33 (Herrero+, 2011)
J/A+A/528/A65 : WASP-12b transits (Maciejewski+, 2011)
J/ApJ/727/125 : Two secondary eclipses of WASP-12b with Spitzer
(Campo+, 2011)
J/A+A/542/A4 : WASP-43b thirty eclipses (Gillon+, 2012)
J/ApJ/755/9 : Spitzer/IRAC light curves of GJ 436 system
(Stevenson+, 2012)
J/ApJ/757/161 : Spectroscopy of 56 exoplanet host stars (Torres+, 2012)
J/MNRAS/419/2233 : HD 80606 transits (Colon+, 2012)
J/A+A/551/A108 : Multi-site obs. of WASP-12 b transit (Maciejewski+, 2013)
J/MNRAS/428/3671 : Transiting planet WASP-19b (Tregloan-Reed+, 2013)
J/MNRAS/436/2 : Transits of WASP-19b (Mancini+, 2013)
J/ApJ/785/126 : HIRES radial velocity measurements (Knutson+, 2014)
J/A+A/588/L6 : WASP-12 transit light curves (Maciejewski+ 2016)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Planet Planet name
13- 25 F13.9 d Per [0.788838/111.4374] Period
27- 32 E6.2 d e_Per [4e-08/0.00072] Lower limit uncertainty in Per
34- 39 E6.2 d E_Per [4e-08/0.00072] Upper limit uncertainty in Per
41 A1 --- l_e [~] Limit flag on e
42- 48 F7.5 --- e [0/0.93286] Eccentricity
50- 56 F7.5 --- e_e [0.00055/0.0043]? Lower limit uncertainty in e
58- 64 F7.5 --- E_e [0.00055/0.014]? Upper limit uncertainty in e
66- 71 F6.2 deg omega [165/328]? Argument of periastron ω
73- 78 F6.2 deg e_omega [0.15/170]? Lower limit uncertainty in omega
80- 85 F6.2 deg E_omega [0.15/115]? Upper limit uncertainty in omega
87- 91 A5 --- Ref1 Reference(s) (1)
93- 97 F5.3 Msun M* [0.556/1.495] Stellar mass
99-103 F5.3 Msun e_M* [0.019/0.065] Lower limit uncertainty in M*
105-109 F5.3 Msun E_M* [0.019/0.08] Upper limit uncertainty in M*
111-115 F5.3 Rsun R* [0.455/1.84] Stellar radius
117-121 F5.3 Rsun e_R* [0.01/0.17] Lower limit uncertainty in R*
123-127 F5.3 Rsun E_R* [0.011/0.17] Upper limit uncertainty in R*
129-132 I4 K Teff [3416/7430] Effective temperature
134-136 I3 K e_Teff [43/120] Lower limit uncertainty in Teff
138-140 I3 K E_Teff [43/200] Upper limit uncertainty in Teff
142-146 A5 --- Ref2 Reference(s) (1)
--------------------------------------------------------------------------------
Note (1): Reference as follows:
1 = Maciejewski et al. (2014AcA....64..323M 2014AcA....64..323M);
2 = von Braun et al. (2012ApJ...753..171V 2012ApJ...753..171V);
3 = Pal et al. (2010MNRAS.401.2665P 2010MNRAS.401.2665P); Lewis et al. (2013ApJ...766...95L 2013ApJ...766...95L);
4 = Wong et al. (2016ApJ...823..122W 2016ApJ...823..122W);
5 = Pal et al. (2008ApJ...680.1450P 2008ApJ...680.1450P) (M*, R*);
6 = Torres et al. (2012, J/ApJ/757/161) (Teff);
7 = Winn et al. (2009ApJ...703.2091W 2009ApJ...703.2091W);
8 = Hebrard et al. (2010, J/A+A/516/A95) (M*, R*);
9 = Moutou et al. (2009, J/A+A/498/L5) (Teff);
10 = Carter et al. (2009ApJ...696..241C 2009ApJ...696..241C);
11 = Baluev et al. (2015MNRAS.450.3101B 2015MNRAS.450.3101B);
12 = de Kok et al. (2013A&A...554A..82D 2013A&A...554A..82D) (M*);
13 = Boyajian et al. (2015MNRAS.447..846B 2015MNRAS.447..846B) (R*, Teff);
14 = Knutson et al. (2007ApJ...655..564K 2007ApJ...655..564K);
15 = Takeda et al. (2007, J/ApJS/168/297) (M*);
16 = Turner et al. (2016MNRAS.459..789T 2016MNRAS.459..789T) (Per, e);
17 = Knutson et al. (2014, J/ApJ/785/126) (ω);
18 = Enoch et al. (2010A&A...516A..33E 2010A&A...516A..33E);
19 = Hebb et al. (2009ApJ...693.1920H 2009ApJ...693.1920H);
20 = Wong et al. (2015ApJ...811..122W 2015ApJ...811..122W);
21 = Joshi et al. (2009MNRAS.392.1532J 2009MNRAS.392.1532J);
22 = Tregloan-Reed et al. (2013, J/MNRAS/428/3671) (M*, R*);
23 = Collier Cameron et al. (2010MNRAS.407..507C 2010MNRAS.407..507C);
24 = Gillon et al. (2012, J/A+A/542/A4).
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Planet Planet name
13- 15 F3.1 um lambda [3.6/8] Wavelength λ
17- 20 F4.2 d P(PSR) [0.46/1.25] Pseudo-synchronous rotation period
PPSR
22- 25 F4.2 d e_P(PSR) [0.01/0.37] Lower limit uncertainty in P(PSR) (1)
27- 30 F4.2 d E_P(PSR) [0/0.5] Upper limit uncertainty in P(PSR) (1)
32- 35 F4.2 d Prot [0.74/3.18] Rotation period
37- 40 F4.2 d e_Prot [0.01/0.71] Lower limit uncertainty in Prot (1)
42- 45 F4.2 d E_Prot [0/0.94] Upper limit uncertainty in Prot (1)
47- 50 F4.1 h taueq [0.3/97] Radiative timescale at a reference
temperature given by the orbit-averaged
equilibrium temperature Teq, τeq
52- 55 F4.1 h e_taueq [0/16.4] Lower limit uncertainty in taueq (1)
57- 60 F4.1 h E_taueq [0.3/34.7] Upper limit uncertainty in taueq (1)
62- 65 I4 K T0 [177/2336] Minimum ("nightside") temperature
67- 69 I3 K e_T0 [13/472] Lower limit uncertainty in T0 (1)
71- 74 I4 K E_T0 [10/1277] Upper limit uncertainty in T0 (1)
76 A1 --- l_A [<] Limit flag on A
77- 80 F4.2 --- A [0.01/0.85] Albedo (2)
82- 85 F4.2 --- e_A [0.01/0.16]? Lower limit uncertainty in A (1)
87- 90 F4.2 --- E_A [0.01/0.15]? Upper limit uncertainty in A (1)
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Note (1): Uncertainties listed are 1σ ranges of a Metropolis-Hastings
algorithm walk around the region of most favorable likelihood in parameter
space.
Note (2): Upper limits imply that the best-fit values are zero, with a 1σ
uncertainty given by the upper limit.
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Planet Planet name
13 A1 --- n_Planet [b] Note on Planet (G1)
15- 30 A16 --- Band Band(s) used for observation
32- 41 F10.5 d Emid [3346.52/5844.82]? Mid time of the eclipse
(BJD-2450000)
43- 49 F7.5 d e_Emid [0.0001/0.012]? Lower limit uncertainty in Emid
51- 57 F7.5 d E_Emid [0.0001/0.012]? Upper limit uncertainty in Emid
58 A1 --- n_Emid [ab] Note on Emid (G1)
60- 66 F7.5 d E1-4 [0.04347/0.274]? Time of the total duration
68- 74 F7.5 d e_E1-4 [0.00021/0.01]? Lower limit uncertainty in E1-4
76- 82 F7.5 d E_E1-4 [0.00023/0.01]? Upper limit uncertainty in E1-4
84- 90 F7.5 d E1-2 [0.005/0.0195]? Time of ingress/egress
(E1,2 = E3,4)
92- 98 F7.5 d e_E1-2 [0.0003/0.005]? Lower limit uncertainty in E1-2
100-106 F7.5 d E_E1-2 [0.0003/0.005]? Upper limit uncertainty in E1-2
108 A1 --- l_Depth [<] Limit flag on Depth
109-117 F9.7 --- Depth [6.93e-05/0.02542]? Eclipse depth
119-127 F9.7 --- e_Depth [6e-07/0.0012]? Lower limit uncertainty
in Depth
129-137 F9.7 --- E_Depth [6e-07/0.0012]? Upper limit uncertainty
in Depth
139-146 A8 --- n_Depth Note on Depth upper limit
148-192 A45 --- Ref Reference(s)
194-233 A40 --- Bibcode Bibcode of the reference(s)
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Planet Planet name
13 A1 --- n_Planet [bc] Note on Planet (1)
15- 25 A11 --- Band Band(s) used for observation
27- 37 F11.6 d Tmid [2826.62/7089.11181]? Mid time of the transit
(BJD-2450000) (2)
39- 46 F8.6 d e_Tmid [1.5e-05/0.011]? Lower limit uncertainty in Tmid
48- 55 F8.6 d E_Tmid [1.5e-05/0.011]? Upper limit uncertainty in Tmid
57 A1 --- n_Tmid [a] Note on Tmid (G1)
59- 65 F7.5 d T1-4 [0.0317/0.485]? Time of the total duration
67- 73 F7.5 d e_T1-4 [0.00016/0.013]? Lower limit uncertainty in T1-4
75- 81 F7.5 d E_T1-4 [0.00016/0.012]? Upper limit uncertainty in T1-4
83- 89 F7.5 d T1-2 [0.01044/0.1083]? Time of ingress/egress
(T1,2 = T3,4)
91- 97 F7.5 d e_T1-2 [0.00014/0.0075]? Lower limit uncertainty
in T1-2
99-105 F7.5 d E_T1-2 [0.00052/0.0075]? Upper limit uncertainty
in T1-2
107-115 F9.7 --- Depth [0.00268/0.02542]? Transit depth
117-125 F9.7 --- e_Depth [4.7e-06/0.00071]? Lower limit uncertainty
in Depth
127-135 F9.7 --- E_Depth [4.7e-06/0.00061]? Upper limit uncertainty
in Depth
137-202 A66 --- Ref Reference(s)
204-264 A61 --- Bibcode Bibcode of the reference(s)
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Note (1): Note as follows:
b = Transit properties are from combined wavelength fits:
c = Transit duration and ingress/egress times are calculated from the
geometric relation described in Seager & Mallen-Ornelas
(2003ApJ...585.1038S 2003ApJ...585.1038S) using the transit properties in Torres et al.
(2008ApJ...677.1324T 2008ApJ...677.1324T).
Note (2): Times are in BJD-2450000, unless otherwise noted. Where the source
authors specify times with respect to the UTC and TDB systems (Eastman et al.
2010PASP..122..935E 2010PASP..122..935E), we choose to quote the TDB time.
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Global notes:
Note (G1): Note as follows:
a = Times are in HJD-2450000;
b = Knutson et al. (2012ApJ...754...22K 2012ApJ...754...22K) reported a combined secondary eclipse
ephemeris.
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History:
From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 17-Jan-2019