J/A+A/698/A223 TOI-771 RV datasets (Lacedelli+, 2025)
A transiting rocky super-Earth and a non-transiting sub-Neptune orbiting the
M dwarf TOI-771.
Lacedelli G., Palle E., Davis Y.T., Luque R., Morello G., Tabernero H.M.,
Zapatero Osorio M.R., Pozuelos F.J., Jankowski D., Nowak G., Murgas F.,
Orell-Miquel J., Akana Murphy J.M., Barkaoui K., Charbonneau D.,
Dransfield G., Ducrot E., Geraldia-Gonzalez S., Irwin J., Jehin E.,
Osborne H.L.M., Pedersen P., Rackham B.V., Scott M.G., Timmermans M.,
Triaud A., Van Eylen V.
<Astron. Astrophys. 698, A223 (2025)>
=2025A&A...698A.223L 2025A&A...698A.223L (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Radial velocities ;
Infrared ; Spectroscopy
Keywords: planets and satellites: composition -
planets and satellites: detection -
planets and satellites: individual: TOI-771
Abstract:
The origin and evolution of the sub-Neptune population is a highly
debated topic in the exoplanet community. With the advent of JWST,
atmospheric studies can now put unprecedented constraints on the
internal composition of this population. In this context, the THIRSTEE
project aims to investigate the population properties of sub-Neptunes
with a comprehensive and demographic approach, providing a homogeneous
sample of precisely characterised sub-Neptunes across stellar spectral
types. We present here the precise characterisation of the planetary
system orbiting one of the THIRSTEE M-dwarf targets, TOI-771 (d=25pc,
V=14.9mag), known to host one planet, TOI-771 b, which has been
statistically validated using TESS observations. We use TESS,
SPECULOOS, TRAPPIST and M-Earth photometry together with 31
high-precision ESPRESSO radial velocities to derive the orbital
parameters and investigate the internal composition of TOI-771 b, as
well as exploring the presence of additional companions in the system.
We derive precise mass and radius for TOI-771 b, a super-Earth with
Rb=1.36±0.10R⊕ and Mb=2.47±0.32M⊕
orbiting every 2.3 days around its host star. Its composition is
consistent with an Earth-like planet, and it adds up to the rocky
population of sub-Neptunes lying below the density gap identified
around M dwarfs. With a 13% precision in mass, a 7% radius precision,
and a warm equilibrium temperature of Teq=543K, TOI-771 b is a
particularly interesting target for atmospheric characterisation with
JWST, and it is indeed one of the targets under consideration for the
Rocky World DDT program. Additionally, we discover the presence of a
second, non-transiting planet in the system, TOI-771 c, with a period
of 7.61 days and a minimum mass of
Mpsin(i)=2.87+0.41-0.38M⊕. Even though the inclination is
not directly constrained, the planet likely belongs to the temperate
sub-Neptune population, with an equilibrium temperature of 365K.
Description:
We collected 31 high-resolution spectra of TOI-771 with the Echelle
SPectrograph for Rocky Exoplanets and Stable Spectroscopic
Observations (ESPRESSO) installed at the ESO Very Large Telescope
telescope array at Paranal Observatory, Chile.
The observations span between December 6, 2023, and March 9, 2024,
covering a total baseline of ∼94 days.
ESPRESSO radial velocity and activity indicators of TOI-771.
Objects:
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RA (2000) DE Designation(s)
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10 56 27.19 -72 59 05.4 TOI-771 = 2MASS J10562716-7259054
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablec1.dat 126 31 ESPRESSO RVs and activity indicators
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Byte-by-byte Description of file: tablec1.dat
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Bytes Format Units Label Explanations
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1- 14 F14.6 d BJD Barycentric Julian Date (TDB)
16- 21 F6.2 m/s RV Radival velocity
23- 26 F4.2 m/s e_RV Radial velocity uncertainty
28- 32 F5.2 m2/s2 dlw Differential line width
34- 37 F4.2 m2/s2 e_dlw Differential line width uncertainty
39- 44 F6.2 m/s CRX Chromatic index
46- 49 F4.2 m/s e_CRX Chromatic index uncertainty
51- 56 F6.4 --- NaI Sodium line index (doublet I)
58- 63 F6.4 --- e_NaI Sodium line index (doublet I) uncertainty
65- 70 F6.4 --- NaII Sodium line index (doublet II)
72- 77 F6.4 --- e_NaII Sodium line index (doublet II) uncertainty
79- 84 F6.4 --- Halpha H-alpha line index
86- 91 F6.4 --- e_Halpha H-alpha line index uncertainty
93- 98 F6.1 m/s FWHM Full width half maximum
100-102 F3.1 m/s e_FWHM Full width half maximum uncertainty
104-109 F6.1 m/s Bis Bisector span
111-113 F3.1 m/s e_Bis Bisector span uncertainty
115-120 F6.3 --- SMW S-index
122-126 F5.3 --- e_SMW S-index uncertainty
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Acknowledgements:
Gaia Lacedelli, glacedelli(at)iac.es
(End) Patricia Vannier [CDS] 25-Apr-2025