J/A+A/685/A56 TOI-238 RV, FWHM, BIS and TESS data (Suarez Mascareno+, 2024)
TESS and ESPRESSO discover a super-Earth and a mini-Neptune orbiting
the K-dwarf TOI-238.
Suarez Mascareno, A., Passegger V.M., Gonzalez Hernandez J.I.,
Armstrong D.J., Nielsen L.D., Lovis C., Lavie B., Sousa S.G., Silva A.M.,
Allart R., Rebolo R., Pepe F., Santos N.C., Cristiani S., Sozzetti A.,
Zapatero Osorio M.R., Tabernero H.M., Dumusque X., Udry S., Adibekyan V.,
Allende Prieto C., Alibert Y., Barros S.C.C., Bouchy F., Castro-Gonzalez A.,
Collins K.A., Damasso M., D'Odorico V., Demangeon O.D.S., Di Marcantonio P.,
Ehrenreich D., Hadjigeorghiou A., Hara N., Hawthorn F., Jenkins J.M.,
Lillo-Box J., Lo Curto G., Martins C.J.A.P., Mehner A., Micela G.,
Molaro P., Nunes N., Nari N., Osborn A., Palle E., Ricker G.R.,
Rodrigues J., Rowden P., Seager S., Stefanov A.K., Strom P.A.,
Villasenor J.N.S., Watkins C.N., Winn J., Wohler B., Zambelli R.
<Astron. Astrophys. 685, A56 (2024)>
=2024A&A...685A..56S 2024A&A...685A..56S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Radial velocities ;
Optical
Keywords: techniques: radial velocities - planets and satellites: composition -
planets and satellites: detection -
planets and satellites: terrestrial planets - stars: activity
Abstract:
The number of super-Earth and mini-Neptune planet discoveries has
increased significantly in the last two decades thanks to transit and
radial velocity surveys. When it is possible to apply both techniques,
we can characterise the internal composition of exoplanets, which in
turn provides unique insights on their architecture, formation and
evolution. We performed a combined photometric and radial velocity
analysis of TOI-238 (TYC 6398-132-1), which has one short-orbit
super-Earth planet candidate announced by NASA's TESS team. We aim to
confirm its planetary nature using radial velocities taken with the
ESPRESSO and HARPS spectrographs, to measure its mass and to detect
the presence of other possible planetary companions. We carried out a
joint analysis by including Gaussian processes and Keplerian orbits to
account for the stellar activity and planetary signals simultaneously.
We detected the signal induced by TOI-238 b in the radial velocity
time-series, and the presence of a second transiting planet,
TOI-238 c, whose signal appears in RV and TESS data. TOI-238 b is a
planet with a radius of 1.402+0.0840.086R⊕_ and a mass of
3.40+0.460.45M⊕. It orbits at a separation of
0.02118±0.00038AU of its host star, with an orbital period of
1.2730988±0.0000029-days, and has an equilibrium temperature of
1311±28K. TOI-238 c has a radius of 2.18±0.18R⊕ and a mass
of 6.7±1.1M⊕. It orbits at a separation of 0.0749±0.0013AU
of its host star, with an orbital period of 8.465652±0.000031-days,
and has an equilibrium temperature of 696±15K. The mass and radius
of planet b are fully consistent with an Earth-like composition,
making it likely a rocky super-Earth. Planet c could be a water-rich
planet or a rocky planet with a small H-He atmosphere.
Description:
Radial velocity, FWHM and BISECTOR data of the observations of TOI-238
with ESPRESSO and HARPS. TESS SAP photometry of TOI-238.
Objects:
------------------------------------------------------
RA (2000) DE Designation(s)
------------------------------------------------------
23 16 55.51 -18 36 23.9 TOI-238 = TYC 6398-132-1
------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
toi238sp.dat 171 116 TOI-238 RV, FWHM and BIS data
toi238te.dat 98 10427 TOI-238 TESS SAP flux data
--------------------------------------------------------------------------------
Byte-by-byte Description of file: toi238sp.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
3- 10 F8.3 d Date Observation date, BJD-2450000
15- 21 F7.3 m/s DRV0 Raw RV measurement (ΔRV)
26- 32 F7.3 m/s DRV1 Offset corrected RV measurement (ΔRV)
38- 43 F6.3 m/s DRVp Planetary RV variation (ΔRV)
49- 54 F6.3 m/s DRVb Planet b RV variation (ΔRV)
60- 65 F6.3 m/s DRVc Planet c RV variation (ΔRV)
71- 76 F6.3 m/s rotRV Rotation RV variation (ΔRV)
82- 87 F6.3 m/s O-CRV Residuals after the fit (GP+2 planet model,
Keplerian) (ΔRV)
94- 98 F5.3 m/s e_RV RV internal uncertainty
103-109 F7.3 m/s FWHM0 Raw FWHM measurement (ΔFWHM)
114-120 F7.3 m/s FWHM1 Offset corrected FWHM measurement (ΔFWHM)
127-131 F5.3 m/s e_FWHM FWHM internal uncertainty
136-142 F7.3 m/s BIS0 Raw BIS measurement (ΔFWHM)
147-153 F7.3 m/s BIS1 Offset corrected BIS measurement (ΔFWHM)
160-164 F5.3 m/s e_BIS FWHM internal uncertainty
171 I1 --- Inst [0/1] Instrument (1)
--------------------------------------------------------------------------------
Note (1): Instruments as follows:
0 = HARPS
1 = ESPRESSO 19
--------------------------------------------------------------------------------
Byte-by-byte Description of file: toi238te.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
2- 10 F9.3 d Date Observation date, BJD-2450000
13- 21 F9.3 ppm Flux SAP flux, 10min bin (ΔFlux)
24- 32 F9.3 ppm DFlux Detrended SAP flux, 10min bin (ΔFlux)
35- 43 F9.3 ppm DFluxb Planet b flux 10min bin (ΔFlux)
46- 54 F9.3 ppm DFluxc Planet c flux 10min bin (ΔFlux)
57- 65 F9.3 ppm RotFlux Rotation flux 10min bin (ΔFlux)
68- 76 F9.3 ppm O-CFlux Residuals after the fit
(GP+2 planet model, Keplerian) (ΔFlux)
80- 87 F8.3 ppm e_Flux Flux internal uncertainties
91- 98 F8.3 ppm e_Flux1 Flux error with jitter
--------------------------------------------------------------------------------
Acknowledgements:
Alejandro Suarez Mascareno, asm(at)iac.es
(End) Patricia Vannier [CDS] 19-Feb-2024