J/A+A/649/A26 TOI-178 six transiting planets (Leleu+, 2021)
Six transiting planets and a chain of Laplace resonances in TOI-178.
Leleu A., Alibert Y., Hara N.C., Hooton M.J., Wilson T.G., Robutel P.,
Delisle J.-B., Laskar J., Hoyer S., Lovis C., Bryant E.M., Ducrot E.,
Cabrera J., Delrez L., Acton J. S., Adibekyan V., Allart R.,
Allende Prieto C., Alonso R., Alves D. Anderson D.R., Angerhausen D.,
Anglada Escude G., Asquier J., Barrado D., Barros S.C.C., Baumjohann W.,
Bayliss D., Beck M., Beck T., Bekkelien A., Benz W., Billot N., Bonfanti A.,
Bonfils X., Bouchy F., Bourrier V., Boue G., Brandeker A., Broeg C.,
Buder M., Burdanov A., Burleigh M.R., Barczy T., Cameron A.C.,
Chamberlain S., Charnoz S., Cooke B.F., Corral Van Damme C., Correia A.C.M.,
Cristiani S., Damasso M., Davies M. B., Deleuil M., Demangeon O.D.S.,
Demory B.-O., Di Marcantonio P., Di Persio G., Dumusque X., Ehrenreich D.,
Erikson A., Figueira P., Fortier A., Fossati L., Fridlund M., Futyan D.,
Gandolfi D., Garcia Munoz A., Garcia L. J., Gill S., Gillen E., Gillon M.,
Goad M. R., Gonzalez Hernandez J.I., Guedel M., Guenther M.N., Haldemann J.,
Henderson B., Heng K., Hogan A. E., Isaak K., Jehin E., Jenkins J.S.,
Jordan A., Kiss L., Kristiansen M.H., Lam K., Lavie B.,
Lecavelier des Etangs A., Lendl M., Lillo-Box J., Lo Curto G., Magrin D.,
Martins C.J.A.P., Maxted P.F.L., McCormac J., Mehner A., Micela G.,
Molaro P., Moyano M., Murray C.A., Nascimbeni V., Nunes N.J., Olofsson G.,
Osborn H.P., Oshagh M., Ottensamer R., Pagano I., Palle E., Pedersen P.P.,
Pepe F.A., Persson C.M., Peter G., Piotto G., Polenta G., Pollacco D.,
Poretti E., Pozuelos F.J., Queloz D., Ragazzoni R., Rando N., Ratti F.,
Rauer H., Raynard L., Rebolo R., Reimers C., Ribas I., Santos N.C.,
Scandariato G., Schneider J., Sebastian D., Sestovic M., Simon A.E.,
Smith A.M.S., Sousa S.G., Sozzetti A., Steller M., Suarez Mascareno A.,
Szabo Gy. M., Segransan D., Thomas N., Thompson S., Tilbrook R.H.,
Triaud A., Turner O., Udry S., Van Grootel V., Venus H., Verrecchia F.,
Vines J.I., Walton N.A., West R.G., Wheatley P.J., Wolter D.,
Zapatero Osorio M.R.
<Astron. Astrophys. 649, A26 (2021)>
=2021A&A...649A..26L 2021A&A...649A..26L (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Radial velocities ; Spectroscopy
Keywords: techniques: photometric - techniques: spectroscopic -
celestial mechanics - planets and satellites: detection -
planets and satellites: dynamical evolution and stability
Abstract:
Determining the architecture of multi-planetary systems is one of the
cornerstones of understanding planet formation and evolution. Resonant
systems are especially important as the fragility of their orbital
configuration ensures that no significant scattering or collisional
event has taken place since the earliest formation phase when the
parent protoplanetary disc was still present. In this context, TOI-178
has been the subject of particular attention since the first TESS
observations hinted at the possible presence of a near 2:3:3 resonant
chain. Here we report the results of observations from CHEOPS,
ESPRESSO, NGTS, and SPECULOOS with the aim of deciphering the peculiar
orbital architecture of the system. We show that TOI-178 harbours at
least six planets in the super-Earth to mini-Neptune regimes, with
radii ranging from 1.152-0.070+0.073 to 2.87-0.13+0.14 Earth
radii and periods of 1.91, 3.24, 6.56, 9.96, 15.23, and 20.71-days.
All planets but the innermost one form a 2:4:6:9:12 chain of Laplace
resonances, and the planetary densities show important variations from
planet to planet, jumping from 1.02+0.28-0.23 to
0.177+0.055-0.061 times the Earth's density between planets c and
d. Using Bayesian interior structure retrieval models, we show that
the amount of gas in the planets does not vary in a monotonous way,
contrary to what one would expect from simple formation and evolution
models and unlike other known systems in a chain of Laplace
resonances. The brightness of TOI-178 (H=8.76mag, J=9.37mag,
V=11.95mag) allows for a precise characterisation of its orbital
architecture as well as of the physical nature of the six presently
known transiting planets it harbours. The peculiar orbital
configuration and the diversity in average density among the planets
in the system will enable the study of interior planetary structures
and atmospheric evolution, providing important clues on the formation
of super-Earths and mini-Neptunes.
Description:
Raw and detrended data from CHEOPS, NGTS, SPECULOOS and TESS; raw data
from ESPRESSO.
Objects:
----------------------------------------------------
RA (2000) DE Designation(s)
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00 29 12.30 -30 27 13.5 TOI-178 = TIC 251848941
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
ch1_det.dat 59 3202 CHEOPS visit 1 detrended fluxes
ch2_det.dat 59 5555 CHEOPS visit 2 detrended fluxes
ch3_det.dat 59 551 CHEOPS visit 3 detrended fluxes
ch4_det.dat 59 392 CHEOPS visit 4 detrended fluxes
ch1_raw.dat 201 3252 CHEOPS visit 1 raw data
ch2_raw.dat 201 5653 CHEOPS visit 2 raw data
ch3_raw.dat 201 559 CHEOPS visit 3 raw data
ch4_raw.dat 201 424 CHEOPS visit 4 raw data
spec.dat 59 36 SPECULOOS data
ng1_det.dat 59 13943 NGTS visit 1 detrended fluxes
ng2_det.dat 59 12840 NGTS visit 2 detrended fluxes
ng1_raw.dat 87 13943 *NGTS visit 1 raw data on night UT 10/09/2019
ng2_raw.dat 87 12840 *NGTS visit 2 raw data on night UT 11/10/2019
espresso.dat 202 46 ESPRESSO data
tess_det.dat 59 18316 TESS sector 2 detrended fluxes
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Note on ng1_raw.dat: The detrend model is of the form:
0.99323949 + 0.005759616 * airmass.
Note on ng2_raw.dat: The detrend model is of the form:
0.99484923 + 0.00492908 * airmass.
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Byte-by-byte Description of file: *_det.dat
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Bytes Format Units Label Explanations
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1- 18 F18.10 d BJD Barycentric Julian date (TDB)
20- 37 F18.16 --- Flux Detrended normalised flux
39- 59 F21.19 --- e_Flux rms uncertainty on detrended normalised flux
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Byte-by-byte Description of file: ch?_raw.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 F17.12 d BJD Barycentric Julian date (BJD-2450000)
19- 36 F18.16 --- Flux Normalised flux
38- 58 F21.19 --- e_Flux Normalised flux error
60- 76 F17.15 --- xshift X shift
78- 94 F17.14 --- yshift Y shift
96-115 F20.16 --- Roll Roll parameter
117-138 F22.20 --- Contam Contamination parameter
140-159 F20.11 --- Bckg Background parameter
161-182 E22.17 --- Smear Smearing parameter
184-201 F18.15 --- deltaT Time span
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Byte-by-byte Description of file: spec.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 F17.12 d BJD Binned barycentric Julain date (BJD-2450000)
19- 36 F18.16 --- DFlux Binned differential flux
38- 59 F22.20 --- e_DFlux Binned differential flux error
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Byte-by-byte Description of file: ng1_raw.dat ng2_raw.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 F16.8 d BJD Barycentric Julian date (TDB)
18- 27 F10.8 --- Flux Normalised target flux
29- 38 F10.8 --- e_Flux Normalised target flux error
40- 49 F10.8 --- DFlux Normalised detrended target flux
51- 60 F10.8 --- AirmassM Airmass detrend model
62- 71 F10.8 --- Model Transit Model
73- 80 F8.6 --- Airmass Airmass
82- 87 I6 --- ID Action IDs
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Byte-by-byte Description of file: espresso.dat
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Bytes Format Units Label Explanations
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1- 18 F18.12 --- RJD Reduced Julian date (JD-2400000)
20- 31 F12.6 km/s RV Radial velocity
33- 40 F8.6 km/s e_RV Radial velocity error
42- 52 F11.6 --- FWHM FWHM of the CCF
54- 61 F8.6 --- e_FWHM FWHM of the CCF error
63- 72 F10.6 --- BISspan Bisector span of the CCF
74- 81 F8.6 --- e_BISspan Bisector span of the CCF error
83- 91 F9.6 --- Contrast Contrast of the CCF
93-100 F8.6 --- e_Contrast Contrast of the CCF error
102-109 F8.6 --- SMW Mount-Wilson S index
111-118 F8.6 --- e_SMW Mount-Wilson S index error
120-127 F8.6 --- Ha Hα activity index
129-136 F8.6 --- e_Ha Hα activity index error
138-145 F8.6 --- Na Na activity index
147-154 F8.6 --- e_Na Na activity index error
156-163 F8.6 --- Ca Ca activity index
165-172 F8.6 --- e_Ca Ca activity index error
174-182 F9.6 --- RHK logR'HK activity index
184-191 F8.6 --- e_RHK logR'HK activity index error
193-202 F10.6 --- BERV Barycentric Earth radial velocity
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Acknowledgements:
Adrien Leleu, leleu.adrien(at)gmail.com
(End) Patricia Vannier [CDS] 17-May-2021