J/A+A/658/A170 TRAPPIST-1 best-fit parameters (Teyssandier+, 2022)
TRAPPIST-1: Dynamical analysis of the transit-timing variations and origin of
the resonant chain.
Teyssandier J., Libert A.-S., Agol E.
<Astron. Astrophys. 658, A170 (2022)>
=2022A&A...658A.170T 2022A&A...658A.170T (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Binaries, orbits
Keywords: celestial mechanics - planet-disc interactions -
protoplanetary discs - planets and satellites: formation -
planets and satellites: dynamical evolution and stability -
planets and satellites: detection
Abstract:
We analyze solutions drawn from the recently published posterior
distribution of the TRAPPIST-1 system, which consists of seven
Earth-size planets appearing to be in a resonant chain around a red
dwarf. We show that all the planets are simultaneously in 2-planet and
3-planet resonances, apart from the innermost pair for which the
2-planet resonant angles circulate. By means of a frequency analysis,
we highlight that the transit-timing variation (TTV) signals possess a
series of common periods varying from days to decades, which are also
present in the variations of the dynamical variables of the system.
Shorter periods (e.g., the TTVs characteristic timescale of 1.3yr)
are associated with 2-planet mean-motion resonances, while longer
periods arise from 3-planet resonances. By use of N-body simulations
with migration forces, we explore the origin of the resonant chain of
TRAPPIST-1 and find that for particular disc conditions, a chain of
resonances -- similar to the observed one -- can be formed which
accurately reproduces the observed TTVs. Our analysis suggests that
while the 4-yr collected data of observations hold key information on
the 2-planet resonant dynamics, further monitoring of TRAPPIST-1 will
soon provide signatures of three-body resonances, in particular the
3.3 and 5.1yr periodicities expected for the current best-fit
solution. Additional observations would help to assess whether the
innermost pair of planets is indeed resonant (its proximity to the 8:5
resonance being challenging to explain), and therefore give additional
constraints on formation scenarios.
Description:
Best-fit parameters of the Trappist-1 planetary system, from Agol et
al. (2021, The Planetary Science Journal, 2, 1). One line per planet,
from planet b to planet h.
Objects:
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RA (2000) DE Designation(s)
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23 06 29.37 -05 02 29.0 Trappist-1 = TIC 278892590
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 151 7 Best-fit parameters of the Trappist-1 planetary
system, from Agol et al. (2021PSJ.....2....1A 2021PSJ.....2....1A)
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See also:
J/AJ/156/178 : NIR transmission spectra of TRAPPIST-1 planets (Zhang+, 2018)
J/AJ/156/218 : Transit light curves of TRAPPIST-1 planets (Ducrot+, 2018)
J/A+A/640/A112 : TRAPPIST-1 transit timings (Ducrot+, 2020)
J/A+A/650/A138 : TRAPPIST-1 analogue stars TESS light curves (Seli+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- Planet [b-h] Planet name
3- 18 E16.11 Msun Mass [0.0/0.01] Planet mass
20- 38 F19.16 d P [1.51/18.78] Orbital period
40- 57 F18.16 au a [0.01/0.07] Semi-major axis
59- 76 F18.16 --- e [0.0/0.01] Eccentricity
78- 95 F18.16 rad inc [1.57/1.58] Orbital Inclination
97-113 F17.15 rad Omega [3.14/3.15] Longitude of ascending node
115-132 F18.16 rad pomega [0.9/5.81] Longitude of pericenter
134-151 F18.16 rad lambda [0.24/6.29] Mean Longitude
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Acknowledgements:
Jean Teyssandier, jeanteyssandier(at)gmail.com
(End) Patricia Vannier [CDS] 14-Jan-2022