J/A+A/666/A187        Gl514 RVs and activity diagnostics        (Damasso+, 2022)
A quarter century of spectroscopic monitoring of the nearby M dwarf Gl514.
A super-Earth on an eccentric orbit moving in and out of the habitable zone.
    Damasso M., Perger M., Almenara J.M., Nardiello D., Perez-Torres M.,
    Sozzetti A., Hara N.C., Quirrenbach A., Bonfils X., Zapatero Osorio M.R.,
    Astudillo-Defru N., Gonzalez Hernandez J.I., Suarez Mascareno A.,
    Amado P.J., Forveille T., Lillo-Box J., Alibert Y., Caballero J.A.,
    Cifuentes C., Delfosse X., Figueira P., Galadi-Enriquez D., Hatzes A.P.,
    Henning T., Kaminski A., Mayor M., Murgas F., Montes D., Pinamonti M.,
    Reiners A., Ribas I., Bejar V.J.S., Schweitzer A., Zechmeister M.
    <Astron. Astrophys. 666, A187 (2022)>
    =2022A&A...666A.187D 2022A&A...666A.187D        (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Radial velocities ;
              Photometry ; Optical
Keywords: techniques: radial velocities - techniques: photometric -
          planetary systems - stars: activity - stars: individual: Gl 514
Abstract:
    Statistical analyses based on Kepler data show that most of the
    early-type M dwarfs host multi-planet systems consisting of Earth to
    sub-Neptune sized planets with orbital periods up to ∼250 days,
    and that at least one such planet is likely located within the
    habitable zone. M dwarfs are therefore primary targets to search for
    potentially habitable planets in the solar neighbourhood.
    We investigated the presence of planetary companions around the nearby
    (7.6pc) and bright (V=9mag) early-type M dwarf Gl 514, analysing 540
    radial velocities collected over nearly 25 years with the HIRES,
    HARPS, and CARMENES spectrographs. The data are affected by
    time-correlated signals at the level of 2-3m/s due to stellar
    activity, that we filtered out testing three different models based on
    Gaussian process regression. As a sanity cross-check, we repeated the
    analyses using HARPS radial velocities extracted with three different
    algorithms. We used HIRES radial velocities and Hipparcos-Gaia
    astrometry to put constraints on the presence of long-period
    companions, and we analysed TESS photometric data.
    We found strong evidence that Gl∼514 hosts a super-Earth on a likely
    eccentric orbit, residing in the conservative habitable zone for
    nearly 34% of its orbital period. The planet Gl 514 b has minimum mass
    mbsinib=5.2±0.9M☉, orbital period Pb=140.43±0.41 days,
    and eccentricity eb=0.45+0.15-0.14. No evidence for transits is
    found in the TESS light curve. There is no evidence for a longer
    period companion in the radial velocities and, based on astrometry, we
    can rule out a ∼0.2M{Jup} planet at a distance of ∼3-10au, and
    massive giant planets/brown dwarfs out to several tens of au. We
    discuss the possible presence of a second low-mass companion at a
    shorter distance from the host than Gl 514 b.
    Gl 514 b represents an interesting science case to study the
    habitability of planets on eccentric orbits. We advocate for
    additional spectroscopic follow-up to get more accurate and precise
    planetary parameters. Further follow-up is also needed to investigate
    sub m/s and shorter period signals.
Description:
    Radial velocities (RVs) of Gl 514 from HARPS and CARMENES-VIS spectra.
    RVs have been extracted from HARPS spectra using three different
    pipelines based on the template matching technique: TERRA, NAIRA
    (included here), and SERVAL (see Trifonov et al., 2020A&A...636A..74T 2020A&A...636A..74T,
    Cat. J/A+A/636/A74). Tables include spectroscopic diagnostics to
    characterize stellar activity.
File Summary:
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 FileName      Lrecl  Records   Explanations
--------------------------------------------------------------------------------
ReadMe            80        .   This file
tablea1.dat       22      162   HARPS RVs extracted with TERRA
tablea2.dat       25      162   HARPS RVs extracted with NAIRA
tablea3.dat       71      162   Activity diagnostics from HARPS spectra
tablea4.dat       22      274   CARMENES-VIS RVs
tablea5.dat       68      272   Activity diagnostics from CARMENES spectra
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See also:
   J/A+A/636/A74 : HARPS radial velocity database (Trifonov+, 2020)
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
   Bytes Format Units   Label     Explanations
--------------------------------------------------------------------------------
   1- 11  F11.6 d       Time      Epochs of the observations (BJD-2450000)
  13- 17  F5.2  m/s     RV        Relative radial velocity
  19- 22  F4.2  m/s   e_RV        Radial velocity uncertainty
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
   Bytes Format Units   Label     Explanations
--------------------------------------------------------------------------------
   1- 11  F11.6 d       Time      Epochs of the observations (BJD-2450000)
  13- 20  F8.2  m/s     RV        Radial velocity
  22- 25  F4.2  m/s   e_RV        Radial velocity uncertainty
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea3.dat
--------------------------------------------------------------------------------
   Bytes Format Units   Label     Explanations
--------------------------------------------------------------------------------
   1- 11  F11.6 d       Time      Epochs of the observations (BJD-2450000)
  13- 18  F6.4  km/s    FWHM      CCF FWHM
  20- 25  F6.4  km/s  e_FWHM      CCF FWHM uncertainties
  27- 33  F7.5  ---     H-alpha   H-alpha activity index
  35- 41  F7.5  ---   e_H-alpha   H-alpha activity index errors
  43- 48  F6.4  ---     CaIIHK    CaIIHK activity index
  50- 55  F6.4  ---   e_CaIIHK    CaIIHK activity index errors
  57- 63  F7.5  ---     NaI       NaI activity index
  65- 71  F7.5  ---   e_NaI       NaI activity index errors
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea4.dat
--------------------------------------------------------------------------------
   Bytes Format Units   Label     Explanations
--------------------------------------------------------------------------------
   1- 11  F11.6 d       Time      Epochs of the observations (BJD-2450000)
  13- 17  F5.2  m/s     RV        Relative radial velocity
  19- 22  F4.2  m/s   e_RV        Radial velocity uncertainty
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea5.dat
--------------------------------------------------------------------------------
   Bytes Format Units   Label     Explanations
--------------------------------------------------------------------------------
   1- 11  F11.6 d       Time      Epochs of the observations (BJD-2450000)
  13- 19  F7.5  --      Ca-IRT    Calcium infrared triplet index
  21- 27  F7.5  --    e_Ca-IRT    Calcium infrared triplet index error
  29- 35  F7.5  --      NaD       Sodium doublet index
  37- 43  F7.5  --    e_NaD       Sodium doublet index error
  45- 50  F6.2  --      dLW       Differential line width
  52- 55  F4.2  --    e_dLW       Differential line width error
  57- 62  F6.2  --      CRX       Chromatic index
  64- 68  F5.2  --    e_CRX       Chromatic index error
--------------------------------------------------------------------------------
Acknowledgements:
    Mario Damasso, mario.damasso(at)inaf.it
(End)  Mario Damasso [INAF-OATo, Italy], Patricia Vannier [CDS]      19-Apr-2022