J/AJ/168/176 TrES-2b: midtransit times and timing residuals (Biswas+, 2024)
Probing the possible causes of the transit timing variation for TrES-2b in the
TESS era.
Biswas S., Bisht D., Jiang I.-G., Sariya D.P., Parthasarathy K.
<Astron. J., 168, 176 (2024)>
=2024AJ....168..176B 2024AJ....168..176B
ADC_Keywords: Exoplanets; Photometry; Optical
Keywords: Hot Jupiters ; Transit timing variation method
Abstract:
Nowadays, transit timing variations (TTVs) are proving to be a very
valuable tool in exoplanetary science to detect exoplanets by
observing variations in transit times. To study the TTV of the hot
Jupiter TrES-2b, we have combined 64 high-quality transit light curves
from all seven sectors of NASA's Transiting Exoplanet Survey Satellite
along with 60 best-quality light curves from the ground-based facility
Exoplanet Transit Database and 106 midtransit times from the previous
works. From the precise transit timing analysis, we have observed a
significant improvement in the orbital ephemerides, but we did not
detect any short-period TTVs that might result from an additional
body. The inability to detect short-term TTVs further motivates us to
investigate long-term TTVs, which might be caused by orbital decay,
apsidal precession, the Applegate mechanism, and the Romer effect, and
the orbital decay appeared to be a better explanation for the observed
TTV with ΔBIC=4.32. The orbital period of the hot Jupiter
TrES-2b appears to be shrinking at a rate of ~-5.58±1.81ms/yr.
Assuming this decay is primarily caused by tidal dissipation within
the host star, we have subsequently calculated the stellar tidal
quality factor value to be ∼9.9x103, which is 2-3 orders of
magnitude smaller than the theoretically predicted values for other
hot-Jupiter systems, and its low value indicates more efficient tidal
dissipation within the host star. Additional precise photometric and
radial velocity observations are required to pinpoint the cause of the
change in the orbital period.
Description:
During the Transiting Exoplanet Survey Satellite (TESS) observing
runs, 64 transits of TrES-2b were observed in a total of seven sectors
(26, 40, 41, 54, 55, 74, and 75) with 120s cadence during the time
interval 2020 June 9 to 2024 January 30. For our work, we directly
downloaded the TESS light-curve files of TrES-2b from the Barbara A.
Mikulski Archive for Space Telescopes (MAST), a public data archive,
and accessed into Presearch Data Conditioning Simple Aperture
Photometry (PDCSAP; Smith+, 2012PASP..124.1000S 2012PASP..124.1000S; Stumpe+,
2012PASP..124..985S 2012PASP..124..985S, 2014PASP..126..100S 2014PASP..126..100S; Caldwell+,
2020RNAAS...4..201C 2020RNAAS...4..201C) light curves. Instead of simple aperture
photometry (SAP) observations, we preferred the PDCSAP light curves
here due to their lower scatter.
In addition to the TESS data, we have also included 60 transit light
curves of TrES-2b with the best-quality data (quality index, DQ<3)
from the Exoplanet Transit Database (ETD;
Poddany+, 2010NewA...15..297P 2010NewA...15..297P), observed during 2013-2023 by several
observers at different observatories all over the globe.
In addition to these, we have also considered all the published light
curves of TrES-2b available in the literature. See Section 2.2.
Objects:
--------------------------------------------------
RA (2000) DE Designation(s)
--------------------------------------------------
19 07 14.03 +49 18 59.0 TrES-2b = Kepler-1b
--------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table4.dat 152 64 The best-fit values of parameters for 64 TESS
transit light curves of TrES-2b using TAP
table5.dat 135 230 Midtransit times and timing residuals for 230
transit light curves of TrES-2b
tablea1.dat 152 60 The best-fit values of parameters for 60 Exoplanet
Transit Database (ETD) transit light curves of
TrES-2b using TAP
--------------------------------------------------------------------------------
See also:
IV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021)
J/MNRAS/343/1131 : 1998-2000 OGLE events microlensing limits (Tsapras+, 2003)
J/ApJ/664/1185 : Three transits of the exoplanet TrES-2 (Holman+, 2007)
J/ApJ/692/L9 : Tidal evol of transiting extrasolar planets (Levrard+, 2009)
J/A+A/500/L45 : Obs of transits of the TrES-2 exoplanet (Mislis+, 2009)
J/A+A/508/1011 : Planetary transit of TrES-1 and TrES-2 (Rabus+, 2009)
J/ApJ/691/1145 : Spectrophotometry of TrES-3 and TrES-4 (Sozzetti+, 2009)
J/ApJ/714/462 : Inclination change of TrES-2b (Scuderi+, 2010)
J/A+A/510/A107 : TrES-2b multi-band transit observations (Mislis+, 2010)
J/MNRAS/408/1494 : Planetary transits of TrES-2 and TrES-3 (Colon+, 2010)
J/A+A/529/A75 : Limb-darkening coefficients (Claret+, 2011)
J/AJ/142/84 : 10 new transit light curves of HAT-P-13b (Fulton+, 2011)
J/A+A/542/A4 : WASP-43b thirty eclipses (Gillon+, 2012)
J/AJ/145/68 : Five new transit light curves of TrES-3 (Jiang+, 2013)
J/ApJ/770/36 : APOSTLE transits: XO-2 syst Photometry,VRI(Kundurthy+, 2013)
J/A+A/551/A108 : Multi-site obs. of WASP-12 b transit (Maciejewski+, 2013)
J/MNRAS/440/1470 : Ji light curves of WTS-2 (Birkby+, 2014)
J/ApJ/785/126 : HIRES radial velocity measurements (Knutson+, 2014)
J/A+A/575/A111 : GAPS V: Global analysis of the XO-2 system (Damasso+, 2015)
J/AJ/151/17 : Eight transiting light curves of WASP-43b (Jiang+, 2016)
J/MNRAS/457/4205 : WASP-22, WASP-41, WASP-42, WASP-55 (Southworth+, 2016)
J/A+A/602/A107 : 231 transiting planets eccentricity and mass (Bonomo+, 2017)
J/A+A/600/A30 : Limb-darkening for TESS satellite (Claret, 2017)
J/AJ/154/4 : Times of transits and occultations: WASP-12b (Patra+, 2017)
J/AcA/68/371 : WASP and KELT planet transits (Maciejewski+, 2018)
J/AJ/155/165 : Dissipation in exoplanet hosts: tidal spin-up (Penev+, 2018)
J/AJ/156/102 : TESS Input Catalog & Candidate Target List (Stassun+, 2018)
J/AJ/157/217 : Transit times: 5 hot Jupiter WASP exoplanets (Bouma+, 2019)
J/AJ/157/242 : Updated study: potential targets for Ariel (Edwards+, 2019)
J/AJ/158/190 : MS hot Jupiter hosts with good astrometry (Hamer+, 2019)
J/ApJ/893/L29 : WASP-4 RVs & hot Jupiter predict P changes (Bouma+, 2020)
J/AJ/159/150 : Transit times of 11 hot Jupiters (Patra+, 2020)
J/A+A/656/A88 : TrES-5 photometric timeseries (Maciejewski+, 2021)
J/AJ/161/72 : 180 Transit & occultation times for WASP-12b (Turner+, 2021)
J/AJ/164/220 : 10 exoplanets from Exoplanet Transit Database (Hagey+, 2022)
J/ApJS/259/62 : TESS transit timing of hot Jupiters (Ivshina+, 2022)
J/ApJS/258/40 : ExoClock project. II. Exoplanet ephemerids (Kokori+, 2022)
J/AJ/163/175 : WASP-12 individual transit fit with TESS (Wong+, 2022)
Byte-by-byte Description of file: table4.dat tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- Epoch [1124/2594] Epoch number
6- 14 F9.7 d Period [2.47062/2.47064] Orbital period
16- 24 F9.7 d E_Period [9.8e-6/1.0e-5] Upper 1σ uncertainty in
period
26- 34 F9.7 d e_Period [9.8e-6/1.0e-5] Lower 1σ uncertainty in
period
36- 48 F13.5 d Time Mid-transit time in Barycentric Julian date;
TDB
50- 56 F7.5 d E_Time [4.6e-4/3.7e-3] Upper 1σ uncertainty in
time
58- 64 F7.5 d e_Time [4.7e-4/3.4e-3] Lower 1σ uncertainty in
time
66- 71 F6.3 deg Inc [83.2/84.2] Orbital inclination
73- 77 F5.3 deg E_Inc [0.04/0.41] Upper 1σ uncertainty in
orbital inclination
79- 83 F5.3 deg e_Inc [0.04/0.41] Lower 1σ uncertainty in
orbital inclination
85- 89 F5.3 --- a/Rs [7.09/7.99] Scaled Semi-major axis in stellar
radii
91- 95 F5.3 --- E_a/Rs [0.048/0.055] Upper 1σ uncertainty in
a/R*
97- 101 F5.3 --- e_a/Rs [0.049/0.055] Lower 1σ uncertainty in
a/R*
103- 108 F6.4 --- Rp/Rs [0.11/0.16] Ratio of planet to star radius
110- 115 F6.4 --- E_Rp/Rs [0.003/0.03] Upper 1σ uncertainty in
Rp/R*
117- 122 F6.4 --- e_Rp/Rs [0.003/0.03] Lower 1σ uncertainty in
Rp/R*
124- 127 F4.2 --- u1 [0.23/0.5] Linear limb-darkening coefficient
129- 132 F4.2 --- E_u1 [0.16/0.2] Upper 1σ uncertainty in u1
134- 137 F4.2 --- e_u1 [0.14/0.2] Lower 1σ uncertainty in u1
139- 142 F4.2 --- u2 [0.17/0.31] Quadratic limb-darkening
coefficient
144- 147 F4.2 --- E_u2 [0.18/0.21] Upper 1σ uncertainty in u2
149- 152 F4.2 --- e_u2 [0.18/0.21] Lower 1σ uncertainty in u2
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 --- Transit [0/2594] Transit number
6- 18 F13.5 d Time Midtransit time in Barycentric Julian date;
TDB
20- 26 F7.5 d E_Time [3e-5/4e-3] Upper 1σ uncertainty in
time
28- 34 F7.5 d e_Time [4e-5/4e-3] Lower 1σ uncertainty in
time
36- 45 F10.7 d O-C [-6e-3/4e-3] Timing residual of linear model
fit
47- 73 A27 --- TransSrc Transit source
75- 93 A19 --- TransBib ADS bibcode for transit source
95- 115 A21 --- TimeSrc Midtransit time source
117- 135 A19 --- TimeBib ADS bibcode for timing source
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [ADS], Robin Leichtnam [CDS] 27-May-2025