J/AJ/163/227 HIRES radial velocity follow up for Kepler-1656 (Angelo+, 2022)
Kepler-1656b's Extreme Eccentricity; Signature of a Gentle Giant.
Angelo I., Naoz S., Petigura E., MacDougall M., Stephan A.P., Isaacson H.,
Howard A.W.
<Astron. J., 163, 227 (2022)>
=2022AJ....163..227A 2022AJ....163..227A
ADC_Keywords: Exoplanets; Stars, variable; Spectra, optical; Radial velocities
Keywords: Exoplanet astronomy ; Exoplanet dynamics ; Extrasolar gaseous
giant planets ; Exoplanet detection methods ; Exoplanet
evolution ; Exoplanet migration
Abstract:
Highly eccentric orbits are one of the major surprises of exoplanets
relative to the solar system and indicate rich and tumultuous
dynamical histories. One system of particular interest is Kepler-1656,
which hosts a sub-Jovian planet with an eccentricity of 0.8.
Sufficiently eccentric orbits will shrink in the semimajor axis due to
tidal dissipation of orbital energy during periastron passage. Here
our goal was to assess whether Kepler-1656b is currently undergoing
such high-eccentricity migration, and to further understand the
system's origins and architecture. We confirm a second planet in the
system with Mc=0.40±0.09Mjup and Pc=1919±27days. We simulated
the dynamical evolution of planet b in the presence of planet c and
find a variety of possible outcomes for the system, such as tidal
migration and engulfment. The system is consistent with an in situ
dynamical origin of planet b followed by subsequent eccentric
Kozai-Lidov perturbations that excite Kepler-1656b's eccentricity
gently, i.e., without initiating tidal migration. Thus, despite its
high eccentricity, we find no evidence that planet b is or has
migrated through the high-eccentricity channel. Finally, we predict
the outer orbit to be mutually inclined in a nearly perpendicular
configuration with respect to the inner planet orbit based on the
outcomes of our simulations and make observable predictions for the
inner planet's spin-orbit angle. Our methodology can be applied to
other eccentric or tidally locked planets to constrain their origins,
orbital configurations, and properties of a potential companion.
Description:
Observations of Kepler-1656 were obtained through the California
Planet Search (CPS) using the High Resolution Echelle Spectrometer on
the Keck I 10m telescope (HIRES). We collected 50 spectra between 2017
July 11 and 2020 October 24. For all observations, spectra were
observed through an iodine cell mounted in front of the spectrometer
for wavelength calibration, with an SNR of 110 per pixel at 500nm.
Objects:
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RA (2000) DE Designation(s)
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18 57 53.32 +39 54 42.5 Kepler-1656 = Kepler-1656
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 44 150 Radial velocity and activity measurements
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See also:
III/159 : Ca II H and K Measurements Made at MWO (Duncan+ 1991)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/ApJ/707/446 : HAT-P-13 photometry follow-up (Bakos+, 2009)
J/A+A/496/513 : RV of 6 stars with long-period giant planets (Moutou+, 2009)
J/other/Sci/330.653 : Detected planets in the Eta-Earth Survey (Howard+, 2010)
J/ApJ/725/875 : Chromospheric activity for CPS stars (Isaacson+, 2010)
J/A+A/523/A15 : HARPS XXIII; RV data for the 8 targets (Naef+, 2010)
J/ApJ/757/18 : Radial velocities 16 hot Jupiter host stars (Albrecht+, 2012)
J/A+A/538/A113 : Extrasolar planets. Radial velocities of 8 stars (Diaz+ 2012)
J/ApJS/208/9 : Intrinsic colors and temperatures of PMS stars (Pecaut+, 2013)
J/ApJ/784/45 : Kepler's multiple planet candidates. III. (Rowe+, 2014)
J/A+A/571/A37 : KOI-1257 photometric and velocimetric data (Santerne+, 2014)
J/ApJS/226/7 : Planet candidates discovered using K2's 1yr (Crossfield+, 2016)
J/A+A/588/L6 : WASP-12 transit light curves (Maciejewski+ 2016)
J/AJ/153/71 : Kepler follow-up observation program I. Imaging (Furlan+, 2017)
J/AJ/154/108 : California-Kepler Survey (CKS). II. Properties (Johnson+, 2017)
J/AJ/154/64 : Transit times of Kepler-448b and Kepler-693b (Masuda, 2017)
J/AJ/153/142 : Radial velocities systems hosting sub-Saturns (Petigura+, 2017)
J/AJ/154/107 : California-Kepler Survey (CKS). I. 1305 stars (Petigura+, 2017)
J/AJ/156/147 : RV and activity measurements of Kepler-1656 (Brady+, 2018)
J/AJ/156/89 : RVs & predicted transittimes for K2-24 system (Petigura+, 2018)
J/AJ/155/89 : California-Kepler Survey (CKS). IV. Planets (Petigura+, 2018)
J/AJ/155/255 : Radial velocity & activity measurements of HATP-11 (Yee+, 2018)
J/AJ/158/181 : Radial velocities and S-index values for HR 5183 (Blunt+, 2019)
J/ApJS/250/29 : Search for nearby Earth analogs. III. RV sets (Feng+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Index [0/150] Internal index number
5- 18 F14.6 d BJD [2457521/2459507] Barycentric Julian Date
20- 26 F7.3 m/s RVel [-19.7/30.7] Barycentric radial velocity
28- 32 F5.3 m/s e_RVel [1.6/2.8] Uncertainty in RVel (1)
34- 38 F5.3 --- SHK [0.12/0.18] The SHK index
40- 44 F5.3 --- e_SHK [0.001] Uncertainty in SHK
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Note (1): These uncertainties are photon-limited.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 15-Sep-2022