J/A+A/693/A164 GL725A RVs and activity indicators (Cortes-Zuleta+, 2025)
Gl 725A b: a potential super-Earth detected with SOPHIE and SPIRou in an M dwarf
binary system at 3.5 pc.
Cortes-Zuleta P., Boisse I., Ould-Elhkim M., Wilson T.G., Larue P.,
Carmona A., Delfosse X., Donati J.-F., Forveille T., Moutou C.,
Collier Cameron A., Artigau E., Acuna L., Altinier L., Astudillo-Defru N.,
Baruteau C., Bonfils X., Cabrit S., Cadieux C., Cook N.J., Decocq E.,
Diaz R.F., Fouque P., Gomes da Silva J., Grankin K., Grouffal S., Hara N.,
Hebrard G., Heidari N., Martins J.H.C., Martioli E., Maurice M.,
Scigliuto J., Serrano Bell J., Sulis S., Petit A.C., Vivien H.G.
<Astron. Astrophys. 693, A164 (2025)>
=2025A&A...693A.164C 2025A&A...693A.164C (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Spectroscopy ;
Radial velocities ; Stars, M-type
Keywords: techniques: radial velocities - planets and satellites: detection -
stars: low-mass - stars: individual: Gl 725A
Abstract:
We report the discovery of a super-Earth candidate orbiting the nearby
mid M dwarf Gl 725A using the radial velocity (RV) method. The
planetary signal has been independently identified using
high-precision RVs from the SOPHIE andSPIRou spectrographs, in the
optical and NIR domains, respectively. We modelled the stellar
activity signal jointly with the planet using two Gaussian Processes,
one for each instrument to account for the chromaticity of the stellar
activity and instrumental systematics, along with a Keplerian model.
The signal is significantly detected with a RV semi-amplitude of
1.67±0.20m/s. The planet Gl 725A b is found to be in an orbit
compatible with circular with a period of 11.2201±0.0051 days. We
analysed 27 sectors of TESS photometry on which no transit event was
found. We determined a minimum mass of Mpsini=2.78±0.35M☉
which places the planet in the super-Earth regime. Using Mass-Radius
relationships we predict a planetary radius to be between 1.2 and
2.0R☉. The proximity of Gl 725A, of only 3.5pc, makes this new
exoplanet one of the closest to Earth and joins the group of S-type
low-mass planets in short orbits (P<15d) around close M dwarfs.
Description:
Radial velocities and activity indicators of Gl 725A, from the SOPHIE
and SPIRou spectrographs. The SOPHIE data consists of 164 observations
taken between March 2021 and December 2023 as part of the subprogram 3
(SP3) of the SOPHIE exoplanet consortium. The observations have
S/N>30, and airmass <1.6. The mean exposure time is 970 s and their
mean SNR is 72 per pixel at 550nm. The SPIRou data consists of 201
observations taken between February 2019 and April 2022 as part of the
Planet Search program (WP1, Moutou et al., 2023A&A...678A.207M 2023A&A...678A.207M, Cat.
J/A+A/678/207) of the SPIRou Legacy Survey (SLS, Donati et al.,
2020MNRAS.498.5684D 2020MNRAS.498.5684D). The observations have S/N>150 and airmass <1.7.
The median exposure time is 61 s per rhomb position (244s for a
complete sequence), and a median S/N per pixel at 1670nm.
Tables include the SOPHIE and SPIRou relative radial velocities and
their activity indicators.
Objects:
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RA (2000) DE Designation(s)
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18 42 46.70 +59 37 49.4 GJ 725 A = TIC 359676790
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 67 164 SOPHIE RVs and activity indicators
(BIS, Halpha, S index, FWHM, CCF contrast)
tablea2.dat 61 201 SPIRou RVs and activity indicators
(FWHM, velocity chromatic slope, Blong)
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 10 F10.4 d BJD Barycentric Julian date (BJD-2400000)
12- 15 F4.1 m/s DRV Relative radial velocity (G1)
17- 19 F3.1 m/s e_DRV Error on DRV
21- 24 F4.1 m/s BIS CCF bisector span
26- 28 F3.1 m/s e_BIS Error on BIS
30- 36 F7.3 --- Halpha ?=999.999 Halpha index (2)
38- 43 F6.3 --- e_Halpha ?=99.999 Error on Halpha (2)
45- 50 F6.3 --- Sindex ?=99.99 S-index calibrated to the Mount Wilson
Observatory system (2)
52- 56 F5.3 --- e_Sindex ?=0 Error on S index
58- 62 F5.3 km/s FWHM CCF FWHM
64- 67 F4.1 % Contrast Contrast of the CCF in % of depth
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Note (2): Values of 999.990 correspond to outliers.
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 18 F18.12 d BJD Barycentric Julian date (BJD-2400000)
21- 24 F4.1 m/s DRV Relative radial velocity (G1)
26- 28 F3.1 m/s e_DRV Error on DRV
30- 34 F5.3 km/s FWHM CCF FWHM
36- 40 F5.3 km/s e_FWHM Error on FWHM
42- 46 F5.1 m/s CVS Chromatic velocity slope
48- 50 F3.1 m/s e_CVS Error on CVS
52- 56 F5.1 G Bl Longitudinal magnetic field
58- 61 F4.1 G e_Bl Error on Bl
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Global notes:
Note (G1): Relative velocities corrected by the BERV, secular acceleration, and
long-term drift due to the stellar companion.
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Acknowledgements:
Pia Cortes Zuleta, pcz1(at)st-andrews.ac.uk
(End) Patricia Vannier [CDS] 22-Nov-2024