J/A+A/627/A116 LSPM J2116+0234 and GJ 686 radial velocities (Lalitha+, 2019)
The CARMENES search for exoplanets around M dwarfs:
Detection of a mini-Neptune around LSPM J2116+0234 and refinement of orbital
parameters of a super-Earth around GJ 686 (BD+18 3421).
Lalitha S., Baroch D., Morales J.C., Passegger V.M., Bauer F.F.,
Cardona Guillen C., Dreizler S., Oshagh M., Reiners A., Ribas I.,
Caballero J.A., Quirrenbach A., Amado P.J., Bejar V.J.S., Colome J.,
Cortes-Contreras M., Galadi-Enriquez D., Gonzalez-Cuesta L., Guenther E.W.,
Hagen H.-J., Henning T., Herrero E., Husser T.-O., Jeffers S.V.,
Kaminski A., Kuerster M., Lafarga M., Lodieu N., Lopez-Gonzalez M.J.,
Montes D., Perger M., Rosich A., Rodriguez E., Rodriguez-Lopez C.,
Schmitt J.H.M.M., Tal-Or L., Zechmeister M.
<Astron. Astrophys. 627, A116 (2019)>
=2019A&A...627A.116L 2019A&A...627A.116L (SIMBAD/NED BibCode)
ADC_Keywords: Stars, M-type ; Stars, dwarfs ; Exoplanets ; Radial velocities
Keywords: stars: individual: LSPM J2116+0234 - stars: individual: GJ 686 -
stars: low-mass - techniques: radial velocities - planetary systems -
stars: activity
Abstract:
Although M dwarfs are known for high levels of stellar activity, they
are ideal targets for the search of low-mass exoplanets with the
radial velocity (RV) method. We report the discovery of a
planetary-mass companion around LSPM J2116+0234 (M3.0 V) and confirm
the existence of a planet orbiting GJ 686 (BD+18 3421; M1.0 V). The
discovery of the planet around LSPM J2116+0234 is based on CARMENES RV
observations in the visual and near-infrared channels. We confirm the
planet orbiting around GJ 686 by analyzing the RV data spanning over
two decades of observations from CARMENES VIS, HARPS-N, HARPS, and
HIRES. We find planetary signals at 14.44 and 15.53d in the RV data
for LSPM J2116+0234 and GJ 686, respectively. Additionally, the RV,
photometric time series, and various spectroscopic indicators show
hints of variations of 42 d for LSPM J2116+0234 and 37 d for GJ 686,
which we attribute to the stellar rotation periods. The orbital
parameters of the planets are modeled with Keplerian fits together
with correlated noise from the stellar activity. A mini-Neptune with a
minimum mass of 11.8M⊕ orbits LSPM J2116+0234 producing a RV
semi- amplitude of 6.19m/s, while a super-Earth of mass 6.6M⊕
orbits GJ 686 and produces a RV semi-amplitude of 3.0m/s. Both LSPM
J2116+0234 and GJ 686 have planetary companions populating the regime
of exoplanets with masses lower than 15M⊕ and orbital periods
<20d.
Description:
We analysed radial velocity data from the CARMENES NIR and VIS
channels for LSPM J2116+0234, and from CARMENES VIS channel, HARPS and
HIRES for GJ 686. All the RVs are corrected for barycentric motion and
secular acceleration. The CARMENES measurements were taken in the
context of the CARMENES search for exoplanets around M dwarfs. The
CARMENES instrument consists of two channels: the VIS channel obtains
spectra at a resolution of R=94600 in the wavelength range 520-960nm,
while the NIR channel yields spectra of R=80400 covering 960-1710nm.
Both channels are calibrated in wavelength with hollow-cathode lamps
and use temperature- and pressure-stabilized Fabry-Perot etalons to
interpolate the wavelength solution and simultaneously monitor the
spectrograph drift during nightly operations (Bauer et al.,
2015A&A...581A.117B 2015A&A...581A.117B).
Objects:
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RA (2000) DE Designation(s)
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21 16 27.28 +02 34 51.39 LSPM J2116+0234 = PM J21164+0234
17 37 53.34 +18 35 30.16 BD+18 3421 = GJ 686
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 40 125 Radial velocities of LSPM J2116+0234
tablea2.dat 36 288 Radial velocities of GJ686
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Byte-by-byte Description of file: tablea1.dat tablea2.dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d BJD Barycentric Julian date of observation
15- 20 F6.2 m/s RV Radial velocity
23- 27 F5.2 m/s e_RV Radial velocity uncertainty
29- 40 A12 --- Inst Instrument (1)
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Note (1): CARMENES, VIS or NIR for LSPMJ21160234 (tablea1),
CARMENES, VIS, HARPS or HIRES for GJ686 (tablea2).
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Acknowledgements:
Sairam Lalitha, lalitha.sairam(at)uni-goettingen.de
(End) Sairam Lalitha [IAG, Germany], Patricia Vannier [CDS] 20-Jun-2019