J/A+A/684/L17 TOI-5398 radial velocity curve (Mantovan+, 2024)
Orbital obliquity of the young planet TOI-5398 b and the evolutionary history of
the system.
Mantovan G., Malavolta L., Locci D., Polychroni D., Turrini D., Maggio A.,
Desidera S., Spinelli R., Benatti S., Piotto G., Lanza A.F., Marzari F.,
Sozzetti A., Damasso M., Nardiello D., Cabona L., D'Arpa M., Guilluy G.,
Mancini L., Micela G., Nascimbeni V., Zingales T.
<Astron. Astrophys. 684, L17 (2024)>
=2024A&A...684L..17M 2024A&A...684L..17M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Radial velocities ;
Optical
Keywords: techniques: radial velocities - planet-star interactions -
stars: individual: BD+37 2118
Abstract:
Multi-planet systems exhibit remarkable architectural diversity.
However, short-period giant planets are typically isolated. Compact
systems like TOI-5398, with an outer close-orbit giant and an inner
small-size planet, are rare among systems containing short-period
giants. TOI-5398's unusual architecture coupled with a young age
(650±150Myr) makes it promising for measuring the original obliquity
between the orbital plane of the giant and the stellar spin axis, to
gain insights into its formation and orbital migration. We collected
in-transit (plus suitable off-transit) observations of TOI-5398 b with
HARPS-N at TNG on March 25, 2023, obtaining high-precision radial
velocity time series that allowed us to measure the
Rossiter-McLaughlin (RM) effect. From the RM effect modelling, we
obtained a sky-projected obliquity of λ=3.0+6.8-4.2deg for
TOI-5398 b, consistent with the planet being aligned. Thanks to the
stellar rotation period knowledge, we estimated the true 3D obliquity
ψ=(13.2±8.2)deg. Based on theoretical considerations, the
orientation we measure is unaffected by tidal effects, offering a
direct diagnostic for understanding the planetary system's formation
path. The orbital characteristics of TOI-5398, with its compact
architecture, eccentricity consistent with circular orbits, and hints
of orbital alignment, appear more compatible with the disc-driven
migration scenario. TOI-5398's relative youth (compared with similar
compact systems) coupled with an exceptional suitability for
transmission spectroscopy studies, presents an outstanding opportunity
to establish a benchmark for exploring the disc-driven migration
model.
Description:
In-transit (plus suitable off-transit) observations of TOI-5398 on
March 25, 2023. A total of 47 spectra, with exposure time of 600s.
This window covers the full 4.3 hr-long transit (26 spectra) and about
4 hours of off-transit baseline (21 spectra), subdivided into ∼2
hours before and after the transit event.
Objects:
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RA (2000) DE Designation(s)
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10 47 31.09 +36 19 45.86 TOI-5398 = BD+37 2118
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 37 47 Radial velocity time-series
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See also:
J/A+A/682/A129 : TOI-5398 spectroscopic time-series (Mantovan+, 2024)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 12 F12.6 d Time Barycentric Julian date, TDB (BJD-2400000)
14- 22 F9.3 m/s RV Radial velocity
24- 28 F5.3 m/s e_RV Radial velocity uncertainty
30- 32 A3 --- Phase [on/off ] Transit phase
34- 37 F4.1 --- S/N Signal-to-noise ratio at 5460Å
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Acknowledgements:
Giacomo Mantovan, giacomo.mantovan(at)unipd.it
(End) Giacomo Mantovan [Unipd, Italy], Patricia Vannier [CDS] 02-Apr-2024