J/A+A/703/A201 TOI-283 radial velocity and activity indices (Murgas+, 2025)
TOI-283 b: a transiting mini-Neptune in a 17.6-day orbit discovered
with TESS and ESPRESSO.
Murgas F., Palle E., Suarez Mascareno A., Korth J., Pozuelos F.J.,
Hobson M.J., Lavie B., Lovis C., Sousa S.G., Bossini D., Parviainen H.,
Castro-Gonzalez A., Adibekyan V., Allende Prieto C., Alibert Y., Bouchy F.,
Briceno C., Caldwell D.A., Ciardi D., Clark C., Collins K.A., Collins K.I.,
Cristiani S., Dumusque X., Ehrenreich D., Figueira P., Furlan E.,
Genova Santos R., Gnilka C., Gonzalez Hernandez J.I., Hartman Z.,
Howell S.B., Jenkins J.M., Law N., Littlefield C., Lo Curto G., Mann A.W.,
Martins C.J.A.P., Mehner A., Micela G., Molaro P., Nunes N.J., Pepe F.,
Rebolo R., Relles H.M., Santos N.C., Scott N.J., Seager S., Sozzetti A.,
Udry S., Watkins C.N., Winn J.N., Zapatero Osorio M.R., Ziegler C.
<Astron. Astrophys. 703, A201 (2025)>
=2025A&A...703A.201M 2025A&A...703A.201M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Spectroscopy ;
Radial velocities ; Optical
Keywords: techniques: photometric - techniques: radial velocities -
planets and satellites: detection -
planets and satellites: individual: TOI-283 b -
stars: individual: TOI-283
Abstract:
Super-Earths and mini-Neptunes are missing from our Solar System, yet
they appear to be the most abundant planetary types in our Galaxy. A
detailed characterization of key planets within this population is
important for understanding the formation mechanisms of rocky and gas
giant planets and the diversity of planetary interior structures.
In 2019, NASA's TESS satellite found a transiting planet candidate
in a 17.6-day orbit around the star TOI-283. We started radial
velocity (RV) follow-up observations with ESPRESSO to obtain a mass
measurement. Mass and radius are measurements critical for planetary
classification and internal composition modeling.
We used ESPRESSO spectra to derive the stellar parameters of the
planet candidate host star TOI-283. We then performed a joint analysis
of the photometric and RV data of this star, using Gaussian processes
to model the systematic noise present in both datasets.
We find that the host is a bright K-type star (d=82.4pc,
Teff=5213±70K, V=10.4mag) with a mass and radius of
M*=0.80±0.01M☉ and R*=0.85±0.03R☉. The planet has an
orbital period of P=17.617-days, a size of Rp=2.34±0.09R⊕,
and a mass of Mp=6.54±2.04M⊕. With an equilibrium
temperature of ∼600 K and a bulk density of
ρp=2.81±0.93g/cm3, this planet is positioned in the
mass-radius diagram where planetary models predict H2O- and
H/He-rich envelopes. The ESPRESSO RV data also reveal a long-term
trend that is probably related to the star's activity cycle. Further
RV observations are required to confirm whether this signal originates
from stellar activity or another planetary body in the system.
Description:
We report the discovery and characterisation of a transiting planet
around the bright K-type star TOI-283 (d=82.4pc, V=10.4mag) using TESS
photometry and ESPRESSO radial velocities. The planet has a period of
17.617days, a radius of 2.34±0.09R⊕, and a mass of
6.54±2.04M⊕, corresponding to a bulk density of
2.81±0.93g/cm3. With an equilibrium temperature of ∼600K, it lies
in the regime where H2O- and H/He-rich envelopes are expected. A
long-term RV trend is also detected, likely related to stellar
activity but possibly due to an additional companion.
Radial velocity and activity indices of TOI-283 taken with
VLT/ESPRESSO.
Objects:
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RA (2000) DE Designation(s)
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07 54 16.71 -65 26 29.5 TOI-283 = TIC 382626661
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablec1.dat 121 84 ESPRESSO radial velocity measurements and
stellar 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- 24 F9.2 m/s RV Radial velocity
26- 29 F4.2 m/s e_RV Radial velocity error
31- 37 F7.2 m/s FWHM Full-width at half maximum of the CCF
39- 42 F4.2 m/s e_FWHM Full-width at half maximum error
44- 49 F6.2 m/s BIS Bisector inverse slope of the CCF
51- 54 F4.2 m/s e_BIS Bisector inverse slope of the CCF error
56- 60 F5.2 --- Cont Contrast of the CCF
62- 65 F4.2 --- e_Cont Contrast of the CCF error
67- 72 F6.4 --- Sindex S-index
74- 79 F6.4 --- e_Sindex S-index error
81- 86 F6.4 --- Na Sodium activity index
88- 93 F6.4 --- e_Na Sodium activity index error
95-100 F6.4 --- Halpha Halpha activity index
102-107 F6.4 --- e_Halpha Halpha activity index error
109-114 F6.4 --- Ca Calcium activity index
116-121 F6.4 --- e_Ca Calcium activity index error
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Acknowledgements:
Felipe Murgas, fmurgas(at)iac.es, ESPRESSO GTO Consortium
(End) Felipe Murgas [IAC, Spain], Patricia Vannier [CDS] 18-Sep-2025