J/AJ/161/82 Photometric & spectroscopic obs. of TOI-954 and K2-329 (Sha+, 2021)
TOI-954 b and K2-329 b: short-period Saturn-mass planets that test whether
irradiation leads to inflation.
Sha L., Huang C.X., Shporer A., Rodriguez J.E., Vanderburg A., Brahm R.,
Hagelberg J., Matthews E.C., Ziegler C., Livingston J.H., Stassun K.G.,
Wright D.J., Crane J.D., Espinoza N., Bouchy F., Bakos G.A., Collins K.A.,
Zhou G., Bieryla A., Hartman J.D., Wittenmyer R.A., Nielsen L.D.,
Plavchan P., Bayliss D., Sarkis P., Tan T.-G., Cloutier R., Mancini L.,
Jordan A., Wang S., Henning T., Narita N., Penev K., Teske J.K., Kane S.R.,
Mann A.W., Addison B.C., Tamura M., Horner J., Barbieri M., Burt J.A.,
Diaz M.R., Crossfield I.J.M., Dragomir D., Drass H., Feinstein A.D.,
Zhang H., Hart R., Kielkopf J.F., Jensen E.L.N., Montet B.T., Ottoni G.,
Schwarz R.P., Rojas F., Nespral D., Torres P., Mengel M.W., Udry S.,
Zapata A., Snoddy E., Okumura J., Ricker G.R., Vanderspek R.K., Latham D.W.,
Winn J.N., Seager S., Jenkins J.M., Colon K.D., Henze C.E.,
Krishnamurthy A., Ting E.B., Vezie M., Villanueva S.
<Astron. J., 161, 82 (2021)>
=2021AJ....161...82S 2021AJ....161...82S
ADC_Keywords: Exoplanets; Stars, G-type; Photometry, infrared; Spectra, optical;
Radial velocities; Stars, masses; Effective temperatures
Keywords: Exoplanet systems ; Photometry ; Transit photometry ; Spectroscopy ;
High resolution spectroscopy ; RV ; G stars ; G dwarf stars ;
G subgiant stars ; Hot Jupiters
Abstract:
We report the discovery of two short-period Saturn-mass planets, one
transiting the G subgiant TOI-954 (TIC44792534, V=10.343, T=9.78)
observed in TESS sectors 4 and 5 and one transiting the G dwarf K2-329
(EPIC246193072, V=12.70, K=10.67) observed in K2 campaigns 12 and 19.
We confirm and characterize these two planets with a variety of
ground-based archival and follow-up observations, including
photometry, reconnaissance spectroscopy, precise radial velocity, and
high-resolution imaging. Combining all available data, we find that
TOI-954b has a radius of 0.852-0.062+0.053RJup and a mass of
0.174-0.017+0.018MJup and is in a 3.68day orbit, while K2-329b
has a radius of 0.774-0.024+0.026RJup and a mass of
0.260-0.022+0.020MJup and is in a 12.46day orbit. As TOI-954b is
30 times more irradiated than K2-329b but more or less the same size,
these two planets provide an opportunity to test whether irradiation
leads to inflation of Saturn-mass planets and contribute to future
comparative studies that explore Saturn-mass planets at contrasting
points in their lifetimes.
Description:
Photometric observations are described in table1. Spectroscopic
observations are described in table4.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 122 10 Summary of Photometric Observations
table2.dat 84 36396 HATSouth Photometric Measurements of TOI-954
table3.dat 28 117 PEST Photometric Measurements of K2-329
table4.dat 112 12 Summary of Spectroscopic Observations
table5.dat 55 48 Precise Radial Velocity Measurements of TOI-954
table6.dat 38 50 Precise Radial Velocity Measurements of K2-329
table10.dat 907 14000 MCMC Samples of the Posterior Distribution of the
TOI-954 System Global Model
table11.dat 706 10000 MCMC Chains from Global Model Fitting of K2-329
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)
J/ApJ/683/1076 : Transits of exoplanet XO-3b (Winn+, 2008)
J/ApJ/710/1724 : Follow-up photometry for HAT-P-11 (Bakos+, 2010)
J/other/Nat/486.375 : Stellar parameters of KOI stars (Buchhave+, 2012)
J/A+A/552/A16 : Limb-darkening for CoRoT, Kepler, Spitzer. II. (Claret+, 2013)
J/AJ/152/182 : iz follow-up photom. of HAT-P-65 and HAT-P-66 (Hartman+, 2016)
J/ApJS/224/2 : K2 EPIC stellar properties for 138600 targets (Huber+, 2016)
J/AJ/152/187 : Planet occur. & stellar metallicity for KOIs (Mulders+, 2016)
J/AJ/152/180 : Bolometric fluxes of eclipsing bin. in Tycho-2 (Stassun+,2016)
J/ApJS/222/14 : Planetary candidates from 1st yr K2 mission (Vanderburg+,2016)
J/A+A/602/A107 : 231 transiting planets eccentricity and mass (Bonomo+, 2017)
J/ApJ/834/17 : Mass & radius of planets, moons, low mass stars (Chen+, 2017)
J/A+A/600/A30 : Limb-darkening for TESS satellite (Claret, 2017)
J/AJ/154/123 : Radial velocity follow-up of HD3167 system (Gandolfi+, 2017)
J/AJ/153/142 : RVs of systems hosting sub-Saturns (Petigura+, 2017)
J/AJ/153/136 : Planets and their host stars with Gaia plxs (Stassun+, 2017)
J/AJ/156/18 : APOGEE DR14:Binary comp. of evolved stars (Price-Whelan+,2018)
J/AJ/155/112 : RVel & light curves for HATS-43-HATS-46 (Brahm+, 2018)
J/AJ/155/89 : California-Kepler Survey (CKS). IV. Planets (Petigura+, 2018)
J/AJ/157/245 : High-precision radial velocities for HD 221416 (Huber+, 2019)
J/AJ/159/19 : SOAR TESS survey. I. (Ziegler+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Name Identification of the source
9- 21 A13 --- Inst Instrument used
23- 45 A23 --- Field Field of view
47 A1 --- f_Inst [d] Flag on Inst (1)
49- 52 I4 yr Obs.Yb [2014/2020] Beginning of observation, year
54- 56 A3 --- Obs.Mb Observation begin, month
58- 59 I2 d Obs.Db Observation begin, day
61- 64 I4 yr Obs.Ye [2015/2017]? Observation end, year
66- 68 A3 --- Obs.Me Observation end, month
70- 71 I2 d Obs.De ? Observation end, day
73 A1 --- Flag [d] Flag on Observation time (1)
75- 79 I5 --- Nobs [78/22351] Number of images (2)
81- 84 I4 s Cad [30/1800] Cadence
86 A1 --- f_Cad [b] Flag on Cad (1)
88- 93 A6 --- Filt Filter used
95-120 A26 --- Note Additional parameter
122 A1 --- f_Note [ace] Flag on Note (1)
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Note (1): Flags as follows:
a = Dilution correction factor applied to the detrended light curve, defined
as the ratio of contaminating flux to total flux
b = Multiplicative factor applied to the quoted noise of the LCOGT light
curves
c = Estimated by taking the median time elapsed between consecutive exposures
and rounding to the nearest 10s
d = Not used for the global model fitting (Section 3.3)
e = Jitter is added in quadrature to the reported noise during the global
model fitting
Note (2): Excluding frames flagged for instrumental or quality issues and
outliers over 4σ (when out of transit)
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 F18.12 d BJD [56838/57116] Barycentric Julian Date at TDB;
BJD-2400000
20- 41 E22.16 mag omag [10.1/12.1] Raw magnitude
43- 50 F8.5 mag mag-epd [10.2/10.5] EPD detrended magnitude (1)
52- 59 F8.5 mag mag-tfa [10.2/10.5] TFA detrended magnitude (2)
61- 82 E22.16 mag e_omag [0.001/0.004] Uncertainty in omag
84- 84 I1 --- f_omag [0/1] Flag on observation (3)
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Note (1): Magnitude detrended using External Parameter Decorrelation
(EPD), Bakos+, 2010, J/ApJ/710/1724.
Note (2): Magnitude detrended using the Trend Filtering Algorithm
(TFA), Kovacs+, 2005MNRAS.356..557K 2005MNRAS.356..557K.
Note (3): A nonzero flag value indicates that an observation is affected by
anomalously high systematics and excluded from the global model.
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 F13.7 d HJD [58071/58073] Heliocentric Julian Date at UTC,
HJD-2400000
15- 21 F7.4 mag omag [12.4/12.5] Observed magnitude
23- 28 F6.4 mag e_omag [0.002/0.005] Uncertainty in omag
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Name Source identifier
9- 25 A17 --- Inst Instrument used
27- 29 A3 --- f_Inst Flag on Inst (1)
31- 34 I4 yr Obs.Yb [2017/2019] Observation begin, year
36- 38 A3 --- Obs.Mb Observation begin, month
40- 41 I2 d Obs.Db Observation begin, day
43- 46 I4 yr Obs.Ye [2018]? Observation end, year
48- 50 A3 --- Obs.Me Observation end, month
52- 53 I2 d Obs.De ? Observation end, day
55- 56 I2 --- Nspec [1/27] Number of spectra
58- 60 I3 103 R [23/130] Resolution (2)
62- 65 F4.1 --- S/Nmin [10/68]? Minimum Signal-to-Noise ratio at
5000Å
67- 70 F4.1 --- S/Nmax [31/90]? Maximum Signal-to-Noise ratio at
5000Å
72 A1 --- f_S/Nmin [c] Flag on Signal-to-Noise (1)
74- 77 I4 0.1nm Wavemin [3500/5000] Minimum wavelength of observation
79- 82 I4 0.1nm Wavemax [6300/9200] Maximum wavelength of observation
84- 87 F4.1 m/s Jit [2.5/17]? Jitter (3)
89- 91 F3.1 m/s e_Jit [1.2/4.7]? Negative error on Jit
93- 95 F3.1 m/s E_Jit [1.7/9.7]? Positive error on Jit
97-104 F8.1 m/s gamma [-16999/16983]? γ parameter (3)
106-108 F3.1 m/s e_gamma [1.4/7.3]? Negative error on gamma
110-112 F3.1 m/s E_gamma [2.9/5.5]? Positive error on gamma
--------------------------------------------------------------------------------
Note (1): Flags as follows:
a = Reconnaissance spectroscopy; no RVs derived for the global model fitting
(Section 3.3)
b = Spectra used to constrain the stellar parameters Teff and metallicity
c = The S/N estimate is unavailable; the rms scatter from the median RV model
is reported instead in Section 2.2.2.
Note (2): Approximate values of typical instrument performance
Note (3): The jitter parameter is added in quadrature to the reported
RVel uncertainties in Tables 5 and 6. The γ parameter is a
constant offset added to RVel measurements of a given RVel instrument.
The jitter and γ values are empirically determined by a global
model fit for each star system (see Section 3.3).
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 F16.8 d BJD [2458536/2458799] Barycentric Julian Date of
observation (1)
18- 28 F11.5 m/s RVel [-8845/36] Absolute relative motion (2)
30- 37 F8.5 m/s e_RVel [0.9/35.27] Uncertainty in RVel
39- 55 A17 --- Tel Telescope/Instrument (CHIRON, CORALIE, HARPS,
MINERVA-Aus, PFS)
--------------------------------------------------------------------------------
Note (1): The MINERVA-Australis measurement at BJD TDB 2458798.2173 is
excluded from the global model because it is a >4σ outlier.
Note (2): The radial velocities given represent absolute relative motion to
the solar system barycenter, except for those from Minerva-Australis and
PFS, where the mean relative motion has been subtracted. See Table 4 for
the constant radial velocity offsets derived by the global model for
each instrument.
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Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 F16.8 d BJD [2458040/2458418] Barycentric Julian Date of
observation
18- 26 F9.2 m/s RVel [-17047/27] Absolute relative motion (1)
28- 32 F5.2 m/s e_RVel [1.4/20] Uncertainty in RVel
34- 38 A5 --- Tel Telescope/Instrument (FEROS, HARPS, PFS)
--------------------------------------------------------------------------------
Note (1): The radial velocities given represent absolute relative motion to
the solar system barycenter, except for those from PFS, where the mean
relative motion has been subtracted. See Table 4 for the constant radial
velocity offsets derived by the global model for each instrument.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table10.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 25 E25.18 [-] lnP [-14371/-14327] natural log, probability
27- 50 E24.18 d Tc [1411.90/1411.92] Time of conjunction, BJD
TDB; -2458000
52- 75 E24.18 d Per [3.68496/3.68499] Period
77-100 E24.18 m/s K [11.5/30.2] RV semiamplitude
102-126 E25.18 --- secosw [-0.42/0.38] sqrt(ecc).cos(ω) (1)
128-152 E25.18 --- sesinw [-0.72/0.43] sqrt(ecc).sin(ω) (1)
154-177 E24.18 --- b [0.0002/0.67] Impact parameter,
b=-a.cos(i)/R*
179-202 E24.18 --- Rp/Rs [0.04/0.06] Ratio, planet/stellar radius
204-227 E24.18 --- q11 [0.006/1] q1, Limb darkening in TESS band (2)
229-252 E24.18 --- q12 [0.0003/1] q2, Limb darkening in TESS band
(2)
254-277 E24.18 --- q21 [0.14/0.73] q1, Limb darkening in r band (2)
279-302 E24.18 --- q22 [0.26/0.65] q2, Limb darkening in r band (2)
304-327 E24.18 --- q31 [0.06/0.61] q1, Limb darkening in z_s band
(2)
329-352 E24.18 --- q32 [0.19/0.59] q1, Limb darkening in z_s band
(2)
354-377 E24.18 Msun Mstar0 [1.09/1.37] Stellar mass, initial
379-402 E24.18 Gyr Age [3.67/8.05] Age
404-427 E24.18 [-] [Fe/H]0 [0.005/0.4] Metallicity, initial
429-452 E24.18 --- DTess [0.01/0.06] Dilution factor, TESS photometric
flux
454-477 E24.18 --- DHATS [7.08e-10/0.0002] Dilution factor, HATSouth
photometric flux
479-502 E24.18 --- CLCOGT [1.63/2.03] Multiplicative uncertainty
factor, LCOGT
504-528 E25.18 m/s gamma1 [-8938/-8734] Constant RV offset, CHIRON
530-554 E25.18 m/s gamma2 [-7359/-7334] Constant RV offset, CORALIE
556-580 E25.18 m/s gamma3 [-7360/-7227] Constant RV offset, HARPS
582-606 E25.18 m/s gamma4 [-33.5/8.45] Constant RV offset, PFS
608-631 E24.18 m/s gamma5 [0.001/58.8] Constant RV offset, Minerva
633-656 E24.18 m/s jitter1 [0.0005/238] Additive RV jitter, CHIRON
658-681 E24.18 m/s jitter2 [0.001/31.6] Additive RV jitter, CORALIE
683-706 E24.18 m/s jitter3 [0.0008/242] Additive RV jitter, HARPS
708-731 E24.18 m/s jitter4 [1.72/34.7] Additive RV jitter, PFS
733-756 E24.18 m/s jitter5 [4.45/60.5] Additive RV jitter, Minerva
758-781 E24.18 mag jitterGaia [5.11e-07/0.2] Additive jitter in magnitude,
Gaia bands
783-806 E24.18 Msun Mstar [0.91/1.54] Stellar mass, current
808-831 E24.18 K Teff [5514/5921] Effective temperature
833-856 E24.18 [cm/s2] logg [3.84/4.11] log, Surface gravity
858-882 E25.18 [-] [Fe/H] [-0.02/0.44] Metallicity, current
884-907 E24.18 mag AVmag [1.43e-05/0.3] Reddening, at V band
--------------------------------------------------------------------------------
Note (1): Parametrization of eccentricity {ecc} and longitude of periastron
ω.
Note (2): Triangular sampling parametrization of the quadratic limb darkening
law by Kipping+, 2013MNRAS.435.2152K 2013MNRAS.435.2152K.
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Byte-by-byte Description of file: table11.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 24 E24.18 [-] lnP [9007/9041] natural log, probability
26- 49 E24.18 d Tc [2940/2941] Time of conjunction, BJD
TDB-2454833
51- 74 E24.18 d Per [12.45/12.46] Period
76- 99 E24.18 m/s K [13.3/31.6] RVel semiamplitude
101-125 E25.18 --- secosw [-0.6/0.32] sqrt(ecc).cos(omega) (1)
127-151 E25.18 --- sesinw [-0.24/0.39] sqrt(ecc).sin(omega) (1)
153-176 E24.18 --- b [0.08/0.51] Impact parameter, b=-a.cos(i)/R*
178-201 E24.18 --- Rp/Rs [0.094/0.099] Ratio, planet/stellar radius
203-226 E24.18 --- q11 [0.19/0.42] q1, Limb darkening in Kepler band
(2)
228-251 E24.18 --- q12 [0.35/0.7] q2, Limb darkening in Kepler band
(2)
253-276 E24.18 --- q21 [0.21/0.98] q1, Limb darkening in Rc band (2)
278-301 E24.18 --- q22 [0.27/0.54] q2, Limb darkening in Rc band (2)
303-326 E24.18 Msun Mstar0 [0.8/1] Stellar mass, initial
328-351 E24.18 Gyr Age [0.04/14] Age
353-377 E25.18 [-] [Fe/H]0 [-0.16/0.31] Metallicity, initial
379-402 E24.18 --- jitterPEST [0.0008/0.004] Additive jitter, PEST
normalized flux
404-428 E25.18 m/s gamma1 [-17018/-16983] Constant RV offset, FEROS
430-454 E25.18 m/s gamma2 [-16997/-16967] Constant RV offset, HARPS
456-480 E25.18 m/s gamma3 [-7.97/14.1] Constant RV offset, PFS
482-505 E24.18 m/s jitter1 [8.7/33.3] Additive RV jitter, FEROS
507-530 E24.18 m/s jitter2 [0.0009/25.2] Additive RV jitter, HARPS
532-555 E24.18 m/s jitter3 [0.234/19.6] Additive RV jitter, PFS
557-580 E24.18 mag jitterGaia [1.7e-06/0.2] Additive jitter in magnitude,
Gaia bands
582-605 E24.18 Msun Mstar [0.745/1.09] Stellar mass, current
607-630 E24.18 K Teff [5143/5446] Effective temperature
632-655 E24.18 [cm/s2] logg [4.46/4.61] log, Surface gravity
657-681 E25.18 [-] [Fe/H] [-0.16/0.359] Metallicity, current
683-706 E24.18 mag AVmag [0.005/0.21] Reddening, at V band
--------------------------------------------------------------------------------
Note (1): Parametrization of eccentricity {ecc} and longitude of periastron
ω.
Note (2): Triangular sampling parametrization of the quadratic limb darkening
law by Kipping+, 2013MNRAS.435.2152K 2013MNRAS.435.2152K.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 08-Apr-2021