J/MNRAS/545/F1703 RV data for Gliese 12 (Turner+, 2026)
The mass of the exo-Venus Gliese 12 b, as revealed by HARPS-N, ESPRESSO, and
CARMENES,
Turner D.A., Eschen Y.N.E., Murgas F., Mortier A., Wilson T.G.,
Fernandez Fernandez J., Gromek N., Morello G., Tabernero H.M., Egger J.A.,
Vissapragada S., Caballero J.A., Dreizler S., Freckelton A.V., Hatzes A.P.,
Lakeland B.S., Nagel E., Naponiello L., Vanaverbeke S., Venner A.,
Zapatero Osorio M.R., Amado P.J., Bejar V.J.S., Bonomo A.S., Buchhave L.A.,
Collier Cameron A., Carleo I., Chaturvedi P., Cloutier R., Damasso M.,
Daspute M., Dholakia S., Dufoer S., Dumusque X., Martinez Fiorenzano A.F.,
Ghedina A., Harutyunyan A., Herrero E., John A.A., Lillo-Box J., Lodieu N.,
Lopez-Morales M., Malavolta L., Mancini L., Mantovan G., Montes D.,
Morales J.C., Nicholson B., Orell-Miquel J., Palethorpe L., Palle E.,
Quirrenbach A., Reffert S., Reiners A., Ribas I., Rice K., Silva A.M.,
<Mon. Not. R. Astron. Soc. 545, F1703 (2026)>
=2026MNRAS.545f1703T 2026MNRAS.545f1703T (SIMBAD/NED BibCode)
ADC_Keywords: Stars, M-type ; Planets ; Stars, double and multiple ;
Exoplanets ; Radial velocities ; Optical
Keywords: planets and satellites: detection -
planets and satellites: terrestrial planets -
planets and satellites: interiors - techniques: radial velocities -
stars: individual: Gliese 12 -
planets and satellites: individual: Gliese 12 b
Abstract:
Small temperate planets are prime targets for exoplanet studies due to
their possible similarities with the rocky planets in the Solar
System. M dwarfs are promising hosts since the planetary signals are
within our current detection capabilities. Gliese 12 b is a
Venus-sized temperate planet orbiting a quiet M dwarf. We present here
the first precise mass measurement of this small exoplanet. We
performed a detailed analysis using HARPS-N, ESPRESSO, and CARMENES
radial velocities, along with new and archival TESS, CHEOPS, and
MuSCAT2/3 photometry data. From fitting the available data, we find
that the planet has a radius of Rp=0.93±0.06REarth and a mass of
Mp=0.95+0.29-0.30MEarth (a 3.2-sigma measurement of the
semi-amplitude K=0.67±0.21m/s), and is on an orbit with a period
of 12.761418+0.000060-0.000055d. A variety of techniques were
utilised to attenuate stellar activity signals. Gliese 12 b has an
equilibrium temperature of Teq=317±8K, assuming an albedo of
zero, and a density consistent with that of Earth and Venus
ρ=6.4±2.4g/cm3. We find that Gliese 12 b has a
predominantly rocky interior and simulations indicate that it is
unlikely to have retained any of its primordial gaseous envelope. The
bulk properties of Gliese 12 b place it in an extremely sparsely
populated region of both mass-radius and density-Teq parameter
space, making it a prime target for follow-up observations, including
Lyman-alpha studies.
Description:
Radial velocity and H-alpha measurements for Gliese 12 (TOI-6251) from
HARPS-N, ESPRESSO and CARMENES. The data processing was
instrument-specific. The HARPS-N spectra were reduced using both the
standard HARPS-N Data Reduction System (DRS) v3.0.1 and, as a
separate, independent reduction, the sBART pipeline (Silva et al.
2022A&A...663A.143S 2022A&A...663A.143S,). The ESPRESSO data were processed with the
ESPRESSO DRS v3.3.1 and also independently with sBART. For CARMENES,
the spectra were reduced using the dedicated SERVAL pipeline
(Zechmeister et al. 2018A&A...609A..12Z 2018A&A...609A..12Z).
Objects:
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RA (2000) DE Designation(s)
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00 15 49.24 +13 33 22.3 Gliese 12 b = TOI-6251.01
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
rv-ha.dat 76 326 Radial velocities and activity indicators
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Byte-by-byte Description of file: rv-ha.dat
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Bytes Format Units Label Explanations
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1- 16 F16.8 d BJD Barycentric Julian date of observation
18- 29 F12.6 m/s RV Radial velocity (relative velocities
for CARMENES data)
31- 39 F9.6 m/s e_RV Radial velocity uncertainty
41- 48 F8.6 [-] Ha H-alpha index
50- 57 F8.6 [-] e_Ha H-alpha index uncertainty
59- 72 A14 [-] Inst Instrument used to take RVs
74 I1 [-] RVout [0/1] RV outlier flag
76 I1 [-] Haout [0/1] H-alpha outlier flag
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Acknowledgements:
Daisy A. Turner, dat936(at)student.bham.ac.uk
References:
Dholakia et al., 2024MNRAS.531.1276D 2024MNRAS.531.1276D,
Gliese 12 b, a temperate Earth-sized planet at 12 parsecs discovered with
TESS and CHEOPS
Kuzuhara et al., 2024ApJ...967L..21K 2024ApJ...967L..21K,
Gliese 12 b: A Temperate Earth-sized Planet at 12 pc Ideal for Atmospheric
Transmission Spectroscopy
Silva et al., 2022A&A...663A.143S 2022A&A...663A.143S,
A novel framework for semi-Bayesian radial velocities through template
matching
Zechmeister et al., 2018A&A...609A..12Z 2018A&A...609A..12Z,
Spectrum radial velocity analyser (SERVAL). High-precision radial velocities
and two alternative spectral indicators
(End) Patricia Vannier [CDS] 24-Feb-2026