J/A+A/688/A172 Radial-velocity measurements for HD 118203 (Maciejewski+, 2024)
Tracking Advanced Planetary Systems (TAPAS) with HARPS-N.
VIII. A wide-orbit planetary companion in the hot-Jupiter system HD 118203.
Maciejewski G., Niedzielski A., Gozdziewski K., Wolszczan A., Villaver E.,
Fernandez M., Adamow M., Sierzputowska J.
<Astron. Astrophys. 688, A172 (2024)>
=2024A&A...688A.172M 2024A&A...688A.172M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Radial velocities ;
Optical
Keywords: planets and satellites: individual: HD 118203 b -
planets and satellites: individual: HD 118203 c -
stars: individual: HD 118203
Abstract:
The star HD 118203, classified as a K0 subgiant, was known to harbour
a transiting hot Jupiter planet on a 6.1-day eccentric orbit. Previous
studies also revealed a linear trend in the radial velocity (RV)
domain, indicative of a companion on a wide orbit. Such a hierarchical
orbital architecture could be helpful in studies of the origins of hot
Jupiters.
We acquired precise RV measurements over 17yr using the 9.2m
Hobby-Eberly Telescope and the 3.6m Telescopio Nazionale Galileo.
Combining these observations with space-born photometric time series
from the Transiting Exoplanet Survey Satellite, we constructed a
two-planetary model for the system. Astrometric observations from
HIPPARCOS and Gaia were used to constrain the orbital inclination of
the wide-orbit companion and its mass. Numerical simulations were used
to investigate the dynamics of the system. The photometric data were
searched for additional transit-like flux drops.
We found that the additional companion is an 11-Jupiter mass planet
orbiting HD 118203 on a 14-yr moderately eccentric orbit, constituting
a hierarchical planetary system with the hot Jupiter. Both planets
were found to be dynamically decoupled mainly due to the general
relativistic apsidal precession of the inner planet, marginalising
secular interactions. The orbits of both planets might have a
relatively low mutual inclination unless the longitudes of the
ascending node differ substantially. This configuration favours the
coplanar high-eccentricity migration as a path to the present-day
orbital configuration. No other transiting planets with radii down to
2 Earth radii and orbital periods less than 100 days were found in the
system.
Description:
We provide the radial-velocity time series for HD 118203. They were
acquired with the High-Resolution Spectrograph (HRS) at the 9.2m
Hobby-Eberly Telescope between January 2006 and June 2013, and with
the High Accuracy RV Planet Searcher in the northern hemisphere
(HARPS-N) at the 3.6m Telescopio Nazionale Galileo between December
2012 and March 2023. The details on observations and data processing
are given in the paper.
Objects:
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RA (2000) DE Designation(s)
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13 34 02.54 +53 43 42.7 HD 118203 = TOI-1271
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 50 51 Doppler observations from HRS
tablea2.dat 50 18 Doppler observations from HARPS-N
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See also:
J/A+A/613/A47 : Radial velocities of 12 evolved stars (Adamow+, 2018)
J/A+A/648/A58 : Radial velocity curves of 4 stars (Niedzielski+, 2021)
Byte-by-byte Description of file: tablea1.dat tablea2.dat
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Bytes Format Units Label Explanations
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1- 16 F16.8 d Tmid Mid-exposure time in Barycentric Julian date
in Barycentric Dynamical Time (BJD_TDB)
18- 29 F12.8 km/s RV Radial velocity measurement
31- 40 F10.8 km/s e_RV Radial velocity error
42- 50 F9.5 m/s BS Bisector span
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Acknowledgements:
Gracjan Maciejewski, gmac(at)umk.pl
Institute of Astronomy, Nicolaus Copernicus University, Poland
References:
Niedzielski et al., Paper I 2015A&A...573A..36N 2015A&A...573A..36N,
A multiple planetary system around the red giant star TYC 1422-614-1.
Adamo et al., Paper II 2015A&A...581A..94A 2015A&A...581A..94A,
Super Li-rich giant HD 107028.
Niedzielski et al., Paper III 2016A&A...588A..62N 2016A&A...588A..62N,
HD 5583 and BD+15 2375 - two cool giants with warm companions.
Niedzielski et al., Paper IV 2016A&A...589L...1N 2016A&A...589L...1N,
TYC 3667-1280-1: The most massive red giant star hosting a warm Jupiter.
Villaver et al., Paper V 2017A&A...606A..38V 2017A&A...606A..38V,
A Massive Jupiter orbiting the very-low-metallicity giant star BD+03 2562
and a possible planet around HD 103485.
Adamow et al., Paper VI 2018A&A...613A..47A 2018A&A...613A..47A, Cat. J/A+A/613/A47
HD 238914 and TYC 3318-01333-1: two more Li-rich giants with planets.
Niedzielski et al., Paper VII 2021A&A...648A..58N 2021A&A...648A..58N, Cat. J/A+A/648/A58
Elder suns with low-mass companions.
(End) Gracjan Maciejewski [Copernicus Univ.], Patricia Vannier [CDS] 29-Jan-2026