Radial velocity homogeneous analysis of M dwarfs observed with HARPS I. Exoplanet detection and candidates

Abstract

The census of planets around M dwarfs in the solar neighbourhood meets two challenges: detecting the best targets for the future characterisation of planets with ELTs, and studying the statistics of planet occurrence that are crucial to formation scenarios. The radial velocity (RV) method remains the most appropriate for such a census as it is sensitive to the widest ranges of masses and periods. HARPS, mounted on the 3.6 m telescope at La Silla Observatory (ESO, Chile), has been obtaining velocity measurements since 2003, and can therefore be used to analyse a very large and homogeneous dataset. We performed a homogeneous analysis of the RV time series of 200 M dwarfs observed with HARPS from 2003 to 2019 (gathering more than 15000 spectra), with the aim of understanding detectable signals such as stellar and planetary companions and activity signals. The RVs were computed with a template matching method before carrying out the time series analysis. First, we focused on the systematic analysis of the presence of a dominant long-term pattern in the RV time series (linear or quadratic trend and sine function). Then, we analysed higher-frequency perdiodic signals using periodograms of the residual time series and Keplerian function fitting. We found long-term variability in 57 RV time series (28.5%). This led to the revision of the parameters of the massive planet (GJ9482 b), as well as the detection of four substellar and stellar companions (around GJ3307, GJ4001, GJ4254, andGJ9588), for which we characterised inclinations and masses by combining RV and astrometry. The periodic analysis allowed us to recover 97% of the planetary systems already published in this sample, but also to propose three new planetary candidates orbiting GJ300 (7.3Me), GJ654(5Me), and GJ739 (39Me), which require additional measurements before they can be confirmed.

References in corpus (48)

• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• A terrestrial planet candidate in a temperate orbit around Proxima Centauri
• Planets and Stellar Activity: Hide and Seek in the CoRoT-7 system
• Assessing statistical significance of periodogram peaks
• Gaia Early Data Release 3: The Gaia Catalogue of Nearby Stars
• A New Planet Around an M Dwarf: Revealing a Correlation Between Exoplanets and Stellar Mass
• A new list of thorium and argon spectral lines in the visible
• Stellar Activity Masquerading as Planets in the Habitable Zone of the M dwarf Gliese 581
• The Hipparcos-Gaia Catalog of Accelerations: Gaia EDR3 Edition
• Trumpeting M Dwarfs with CONCH-SHELL: a Catalog of Nearby Cool Host-Stars for Habitable ExopLanets and Life
• The HARPS search for southern extra-solar planets. X. A m sin i = 11 Mearth planet around the nearby spotted M dwarf GJ 674
• Combining high-dispersion spectroscopy (HDS) with high contrast imaging (HCI): Probing rocky planets around our nearest neighbors
• Gaia Early Data Release 3: Summary of the contents and survey properties
• Magnetic Cycles and Rotation Periods of Late Type Stars from photometric time series
• The New Generation Planetary Population Synthesis (NGPPS). IV. Planetary systems around low-mass stars
• Magnetic activity in the HARPS M-dwarf sample. The rotation-activity relationship for very low-mass stars through R'HK
• Bayesian search for low-mass planets around nearby M dwarfs. Estimates for occurrence rate based on global detectability statistics
• The CARMENES search for exoplanets around M dwarfs -- Planet occurrence rates from a subsample of 71 stars
• The Solar Neighborhood XXXV: Distances to 1404 M Dwarf Systems Within 25 pc in the Southern Sky
• The 10 parsec sample in the Gaia era
• A Long-Period Jupiter-Mass Planet Orbiting the Nearby M Dwarf GJ849
• The HARPS search for southern extra-solar planets: XIV. Gl 176b, a super-Earth rather than a Neptune, and at a different period
• orvara: An Efficient Code to Fit Orbits using Radial Velocity, Absolute, and/or Relative Astrometry
• Two planets around Kapteyn's star : a cold and a temperate super-Earth orbiting the nearest halo red-dwarf
• Line-by-line velocity measurements, an outlier-resistant method for precision velocimetry
• A temperate exo-Earth around a quiet M dwarf at 3.4 parsecs
• GJ 832c: A super-earth in the habitable zone
• The HARPS search for southern extra-solar planets XXXV. Planetary systems and stellar activity of the M dwarfs GJ 3293, GJ 3341, and GJ 3543
• Planetary system LHS 1140 revisited with ESPRESSO and TESS
• Disentangling Planets and Stellar Activity for Gliese 667C
• A Jupiter-like Planet Orbiting the Nearby M Dwarf GJ832
• The HARPS search for southern extra-solar planets XLII. A system of Earth-mass planets around the nearby M dwarf YZ Ceti
• The Solar Neighborhood. XXXIV. A Search for Planets Orbiting Nearby M Dwarfs using Astrometry
• HADES RV Programme with HARPS-N at TNG XV. Planetary occurrence rates around early-M dwarfs
• The SOPHIE search for northern extrasolar planets. XIV. A temperate ($T_{\mathrm{eq}}\sim 300$ K) super-earth around the nearby star Gliese 411
• The Volume-Complete Sample of M Dwarfs with Masses 0.1 <= M/M_sol <= 0.3 within 15 Parsecs
• The GL 569 Multiple System
• TOI-1278 B: SPIRou unveils a rare Brown Dwarf Companion in Close-In Orbit around an M dwarf
• Improving exoplanet detection capabilities with the false inclusion probability. Comparison with other detection criteria in the context of radial velocities
• The SPIRou Legacy Survey Rotation period of quiet M dwarfs from circular polarization in near-infrared spectral lines: I. The SPIRou APERO analysis
• Characterisation of stellar activity of M dwarfs. I. Long-timescale variability in a large sample and detection of new cycles
• Search for Nearby Earth Analogs. II. detection of five new planets, eight planet candidates, and confirmation of three planets around nine nearby M dwarfs
• Masses for the seven planets in K2-32 and K2-233. Four diverse planets in resonant chain and the first young rocky worlds
• The mass of planet GJ676A b from ground-based astrometry: A planetary system with two mature gas giants suitable for direct imaging
• A super-Earth orbiting the nearby M-dwarf GJ 536
• The CARMENES search for exoplanets around M dwarfs. Two terrestrial planets orbiting G 264-012 and one terrestrial planet orbiting Gl 393
• Dynamical masses for two M1 + mid-M dwarf binaries monitored during the SPHERE-SHINE survey
• A super-Earth on a close-in orbit around the M1V star GJ 740. A HADES and CARMENES collaboration

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• NIRPS joining HARPS at ESO 3.6 m. On-sky performance and science objectives
• TOI-2322: two transiting rocky planets close to the stellar rotation period and its first harmonic
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• Direct detections of white dwarfs in four WD+dM post-common envelope binaries within 20 pc
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