J/A+A/675/A141 HN Lib radial velocities (Gonzalez-Alvarez+, 2023)
The CARMENES search for exoplanets around M dwarfs A sub-Neptunian mass planet
in the habitable zone of HN Lib.
Gonzalez-Alvarez E., Kemmer J., Chaturvedi P., Caballero J.A.,
Quirrenbach A., Amado P.J., Bejar V.J.S., Cifuentes C., Herrero E.,
Kossakowski D., Reiners A., Ribas I., Rodriguez E., Rodriguez-Lopez C.,
Sanz-Forcada J., Shan Y., Stock S., Tabernero H.M., Tal-Or L.,
Zapatero Osorio M.R., Hatzes A.P., Henning T., Lopez-Gonzalez M.J.,
Montes D., Morales J.C., Palle E., Pedraz S., Perger M., Reffert S.,
Sabotta S., Schweitzer A., Zechmeister M.
<Astron. Astrophys., 675, A141 (2023)>
=2023A&A...675A.141G 2023A&A...675A.141G (SIMBAD/NED BibCode)
ADC_Keywords: Stars, M-type ; Exoplanets ; Radial velocities ; Optical ;
Infrared
Keywords: techniques: photometric - techniques: radial velocities -
stars: individual: HN Lib - stars: late-type - planetary systems
Abstract:
We report the discovery of HN Lib b, a sub-Neptunian mass planet
orbiting the nearby (d∼6.25pc) M4.0 V star HN Lib detected by our
CARMENES radial-velocity (RV) survey. We determined a planetary
minimum mass of Mbsini=5.46±0.75MEarth and an orbital period of
Pb=36.116±0.029d, using ∼5yr of CARMENES data, as well as archival
RVs from HARPS and HIRES spanning more than 13yr. The flux received by
the planet equals half the instellation on Earth, which places it in
the middle of the conservative habitable zone (HZ) of its host star.
The RV data show evidence for another planet candidate with
M[c]sini=9.7±1.9MEarth and P[c]=113.46±0.20d. The long-term
stability of the signal and the fact that the best model for our data
is a two-planet model with an independent activity component stand as
strong arguments for establishing a planetary origin. However, we
cannot rule out stellar activity due to its proximity to the rotation
period of HN Lib, which we measured using CARMENES activity indicators
and photometric data from a ground-based multi-site campaign as well
as archival data. The discovery adds HN Lib b to the shortlist of
super-Earth planets in the habitable zone of M dwarfs, but HN Lib [c]
probably cannot be inhabited because, if confirmed, it would most
likely be an icy giant.
Description:
HN Lib was spectroscopically observed with CARMENES between 27 January
2016 and 31 December 2020, resulting in a total of 94 RV measurements.
CARMENES is installed at the 3.5m telescope of the Calar Alto
Observatory in Almeria (Spain). It was specifically designed to
deliver high-resolution spectra at optical (resolving power R∼94600)
and near-infrared (R∼80400) wavelengths covering the range from 520nm
to 1710nm. CARMENES has two different channels, one for the optical
(the VIS channel) and one for the near-infrared (the NIR channel) with
a dichroic at 960nm. All data were acquired with integration times of
1800s, which is the maximum exposure time employed for precise RV
measurements with CARMENES.
Objects:
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RA (2000) DE Designation(s)
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14 34 16.81 -12 31 10.4 HN Lib = TIC 294401924
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablec1.dat 136 101 RVs and spectral activity indicators of
HN Lib obtained with CARMENES
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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- 13 F13.5 d BJD Baricentric Julian Date
15- 19 F5.2 m/s RV ?=- Radial velocity
21- 24 F4.2 m/s e_RV ?=- Radial velocity error
26- 31 F6.4 0.1nm CaIIIRTb ?=- CaII IRT b activity index
33- 38 F6.4 0.1nm e_CaIIIRTb ?=- CaII IRT b activity index error
41- 48 F8.5 0.1nm He0830 ?=- He λ0830Å activity index
50- 56 F7.5 0.1nm e_He0830 ?=- He λ0830Å activity index error
59- 66 F8.5 0.1nm Pa/3 ?=- Pa/3 activity index
68- 74 F7.5 0.1nm e_Pa/3 ?=- Pa/3 activity index error
76- 82 F7.5 0.1nm TiO7048 ?=- TiO λ7048Å activity index
84- 90 F7.5 0.1nm e_TiO7048 ?=- TiO λ7048Å activity index error
92- 98 F7.5 0.1nm TiO8428 ?=- TiO λ8428Å activity index
100-106 F7.5 0.1nm e_TiO8428 ?=- TiO λ8428Å activity index error
108-114 F7.5 0.1nm TiO8858 ?=- TiO λ8858Å activity index
116-122 F7.5 0.1nm e_TiO8858 ?=- TiO λ8858Å activity index error
124-129 F6.4 0.1nm VO7940 ?=- VO λ7940Å activity index
131-136 F6.4 0.1nm e_VO7940 ?=- VO λ7940Å activity index error
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 02-Nov-2023