J/A+A/692/A238 TOI-406 RV datasets (Lacedelli+, 2024)
Characterisation of TOI-406 as showcase of the THIRSTEE program.
A two-planet system straddling the M-dwarf density gap.
Lacedelli G., Palle E., Luque R., Cadieux C., Akana Murphy J.M., Murgas F.,
Zapatero Osorio M.R., Tabernero H.M., Collins K.A., Watkins C.N.,
L'Heureux A., Doyon R., Jankowski D., Nowak G., Artigau E., Batalha N.M.,
Bean J.L., Bouchy F., Brady M., Canto Martins B.L., Carleo I., Cointepas M.,
Conti D.M., Cook N.J., Crossfield I.J.M., Gonzalez Hernandez J.I.,
Lewin P., Nari N., Nielsen L.D., Orell-Miquel J., Parc L., Schwarz R.P.,
Srdoc G., Van Eylen V.
<Astron. Astrophys. 692, A238 (2024)>
=2024A&A...692A.238L 2024A&A...692A.238L (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Radial velocities ;
Optical ; Infrared
Keywords: planets and satellites: detection -
planets and satellites: composition -
planets and satellites: individual: TOI-406
Abstract:
The exoplanet sub-Neptune population currently poses a conundrum. Are
small-size planets volatile-rich cores without atmosphere, or are they
rocky cores surrounded by H-He envelope? To test the different
hypotheses from an observational point of view, a large sample of
small-size planets with precise mass and radius measurements is the
first necessary step. On top of that, much more information will
likely be needed, including atmospheric characterisation and a
demographic perspective on their bulk properties. We present here the
concept and strategy of the THIRSTEE project, which aims at shedding
light on the composition of the sub-Neptune population across stellar
types by increasing their number and improving the accuracy of bulk
density measurements, as well as investigating their atmospheres and
performing statistical, demographic analysis. We report the first
results of the program, characterising a new 2 planet system around
the M-dwarf TOI-406. We analyse TESS and ground-based photometry
together with high-precision ESPRESSO and NIRPS/HARPS radial
velocities (RVs) to derive the orbital parameters and investigate the
internal composition of the 2 planets orbiting TOI-406. TOI-406 hosts
two planets with radii and masses of Rc=1.32R⊕,
Mc=2.08M⊕ and Rb=2.08R⊕, Mb=6.57M⊕,
orbiting with periods of 3.3 and 13.2 days, respectively. The inner
planet is consistent with an Earth-like composition, while the
external is compatible with multiple internal composition models,
including volatile-rich planets without H/He atmospheres. The two
planets are located in two distinct regions in the mass-density
diagram, supporting the existence of a density gap among small
exoplanets around M dwarfs. With an equilibrium temperature of only
Teq=368K, TOI-406 b stands up as a particularly interesting target
for atmospheric characterisation with JWST in the low-temperature
regime.
Description:
ESPRESSO, NIRPS and HARPS radial velocity and activity indicators of
TOI-406.
Objects:
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RA (2000) DE Designation(s)
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03 17 02.97 -42 14 32.5 TOI-406 = Gaia DR3 4851053999056603904
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablec1.dat 138 43 ESPRESSO RVs and activity indicators
tablec2.dat 58 101 NIRPS RVs and activity indicators
tablec3.dat 54 43 HARPS 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- 20 F5.2 m/s RV Radival velocity
22- 25 F4.2 m/s e_RV Radial velocity uncertainty
27- 31 F5.2 m2/s2 dlw Differential line width
33- 36 F4.2 m2/s2 e_dlw Differential line width uncertainty
38- 43 F6.2 m/s CRX Chromatic index
45- 48 F4.2 m/s e_CRX Chromatic index uncertainty
50- 55 F6.4 --- NaI Sodium line index (doublet I)
57- 62 F6.4 --- e_NaI Sodium line index (doublet I) uncertainty
64- 69 F6.4 --- NaII Sodium line index (doublet II)
71- 76 F6.4 --- e_NaII Sodium line index (doublet II) uncertainty
78- 83 F6.4 --- Halpha H-alpha line index
85- 90 F6.4 --- e_Halpha H-alpha line index uncertainty
92- 97 F6.1 m/s FWHM Full width half maximum
99-101 F3.1 m/s e_FWHM Full width half maximum uncertainty
103-109 F7.1 m/s Bis Bisector span
111-113 F3.1 m/s e_Bis Bisector span uncertainty
115-119 F5.3 --- SMW S-index
121-125 F5.3 --- e_SMW S-index uncertainty
127-132 F6.3 --- Cont Contrast of the CCF
134-138 F5.3 --- e_Cont Contrast of the CCF uncertainty
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Byte-by-byte Description of file: tablec2.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- 23 F8.2 m/s RV Radial velocity
25- 28 F4.2 m/s e_RV Radial velocity uncertainty
30- 35 F6.1 m/s FWHM Full width half maximum
37- 40 F4.1 m/s e_FWHM Full width half maximum uncertainty
42- 50 F9.7 --- Cont Contrast of the CCF
52- 58 E7.2 --- e_Cont Contrast of the CCF uncertainty
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Byte-by-byte Description of file: tablec3.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- 23 F8.2 m/s RV Radial velocity
25- 28 F4.2 m/s e_RV Radial velocity uncertainty
30- 35 F6.1 m/s FWHM Full width half maximum
37- 40 F4.1 m/s e_FWHM Full width half maximum uncertainty
42- 47 F6.4 --- Cont Contrast of the CCF
49- 54 F6.4 --- e_Cont Contrast of the CCF uncertainty
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Acknowledgements:
Gaia Lacedelli, glacedelli(at)iac.es
(End) Patricia Vannier [CDS] 13-Nov-2024