J/A+A/648/A20 GJ 740 radial velocities (Toledo-Padron+, 2021)
A super-Earth on a close-in orbit around the M1V star GJ 740.
A HADES and CARMENES collaboration.
Toledo-Padron B., Suarez Mascareno A., Gonzalez Hernandez J.I., Rebolo R.,
Pinamonti M., Perger M., Scandariato G., Damasso M., Sozzetti A.,
Maldonado J., Desidera S., Ribas I., Micela G., Affer L.,
Gonzalez-Alvarez E., Leto G., Pagano I., Zanmar Sanchez R., Giacobbe P.,
Herrero E., Morales J.C., Amado P.J., Caballero J.A., Quirrenbach A.,
Reiners A., Zechmeister M.
<Astron. Astrophys. 648, A20 (2021)>
=2021A&A...648A..20T 2021A&A...648A..20T (SIMBAD/NED BibCode)
ADC_Keywords: Stars, dwarfs ; Exoplanets; Radial velocities
Keywords: techniques: radial velocities - techniques: photometric -
instrumentation: spectrographs - stars: individual: GJ 740 -
stars: activity - planets and satellites: detection
Abstract:
M-dwarfs have proven to be ideal targets for planetary radial velocity
(RV) searches due to their higher planet-star mass contrast, which
favors the detection of low-mass planets. The abundance of super-Earth
and Earth-like planets detected around this type of stars encourages
us to continue this search on hosts without reported planetary
companions. The HADES and CARMENES programs aim to carry out extensive
searches of exoplanetary systems around M-type stars in the northern
hemisphere, allowing us to address statistically the properties of the
planets orbiting these objects. In this work, we performed a
spectroscopic and photometric study on one of the program stars
(GJ 740), which exhibits a short-period RV signal compatible with a
planetary companion. We carried out a spectroscopic analysis based on
129 HARPS-N spectra taken over a time-span of 6 yr combined with 57
HARPS spectra taken over 4yr, and 32 CARMENES spectra taken during
more than 1 yr, resulting in a dataset with a time coverage of 10yr.
We also relied on 459 measurements from the public ASAS survey with
a time-coverage of 8yr along with 5yr of photometric magnitudes from
the EXORAP project taken in the V, B, R and I filters to carry out a
photometric study. Both analyses were made using Markov Chain Monte
Carlo (MCMC) simulations and Gaussian Process regression to model the
activity of the star. We present the discovery of a short-period
super-Earth with an orbital period of 2.37756+0.00013-0.00011d and
a minimum mass of 2.96+0.50-0.48Me. We update the previously
reported characterization of the magnetic cycle and rotation period of
the star, obtaining values of Prot=35.563±0.071d and
Pcycle=2800±150d. The RV time-series exhibits a possibly periodic
long-term signal which might be related to a Saturn-mass planet of
∼100Me.
Description:
We used the TERRA reduction software to compute the HARPS-N RVs of GJ
740. Thi s time-series is composed by 129 measurements taken over a
time-span of 6yr. This dataset presents a RV mean uncertainty of
0.8m/s with a RMS of 5.8m/s. We used the CARACAL pipeline to compute
the CARMENES RVs of GJ 740. This time-series is composed by 32
measurements taken over a time-span of 1yr. This dataset presents a RV
mean uncertainty of 1.8m/s with a RMS of 4.3m/s.
Objects:
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RA (2000) DE Designation(s)
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18 58 08.14 +05 54 29.24 GJ 740 = HD 176029
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 56 119 GJ 740 HARPS-N RV
table2.dat 56 55 GJ 740 HARPS RV
table3.dat 36 27 GJ 740 CARMENES RV
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Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 16 F16.8 d BJD Barycentric Julian date (BJD)
19- 36 F18.12 m/s RV Radial velocity
39- 56 F18.16 m/s e_RV Radial velocity uncertainty
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d BJD Julian date (BJD)
16- 25 F10.7 m/s RV Radial velocity
28- 36 F9.7 m/s e_RV Radial velocity uncertainty
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Acknowledgements:
Borja Toledo Padron, btoledo(at)iac.es
(End) Patricia Vannier [CDS] 12-Feb-2021