A planetary system around the nearby M dwarf GJ 667C with at least one super-Earth in its habitable zone

Abstract

We re-analyze 4 years of HARPS spectra of the nearby M1.5 dwarf GJ 667C available through the ESO public archive. The new radial velocity (RV) measurements were obtained using a new data analysis technique that derives the Doppler measurement and other instrumental effects using a least-squares approach. Combining these new 143 measurements with 41 additional RVs from the Magellan/PFS and Keck/HIRES spectrometers, reveals 3 additional signals beyond the previously reported 7.2-day candidate, with periods of 28 days, 75 days, and a secular trend consistent with the presence of a gas giant (Period sim 10 years). The 28-day signal implies a planet candidate with a minimum mass of 4.5 Mearth orbiting well within the canonical definition of the star's liquid water habitable zone, this is, the region around the star at which an Earth-like planet could sustain liquid water on its surface. Still, the ultimate water supporting capability of this candidate depends on properties that are unknown such as its albedo, atmospheric composition and interior dynamics. The 75-day signal is less certain, being significantly affected by aliasing interactions among a potential 91-day signal, and the likely rotation period of the star at 105 days detected in two activity indices. GJ 667C is the common proper motion companion to the GJ 667AB binary, which is metal poor compared to the Sun. The presence of a super-Earth in the habitable zone of a metal poor M dwarf in a triple star system, supports the evidence that such worlds should be ubiquitous in the Galaxy.

Accepted in ApJ Letters, 16 pages, 3 figures and 1 table

References in corpus (5)

• One or more bound planets per Milky Way star from microlensing observations
• Habitable planets around the star Gl 581?
• Comparative statistics and origin of triple and quadruple stars
• On the Eccentricity Distribution of Exoplanets from Radial Velocity Surveys
• Selection Functions in Doppler Planet Searches

Cited by in corpus (94)

• The Occurrence Rate of Small Planets around Small Stars
• The MUSCLES Treasury Survey I: Motivation and Overview
• Target Selection for the Apache Point Observatory Galactic Evolution Experiment (APOGEE)
• A dynamically-packed planetary system around GJ667C with three super-Earths in its habitable zone
• A revised estimate of the occurrence rate of terrestrial planets in the habitable zones around kepler m-dwarfs
• A Spectroscopic Catalog of the Brightest (J<9) M Dwarfs in the Northern Sky
• The Ultraviolet Radiation Environment Around M dwarf Exoplanet Host Stars
• Abiotic O${}_2$ Levels on Planets around F, G, K, and M Stars: Possible False Positives for Life?
• An Excess of Jupiter Analogs in Super-Earth Systems
• Bayesian search for low-mass planets around nearby M dwarfs. Estimates for occurrence rate based on global detectability statistics
• The TRENDS High-Contrast Imaging Survey. IV. The Occurrence Rate of Giant Planets around M-Dwarfs
• Extrasolar planets in stellar multiple systems
• Exoplanet Biosignatures: Observational Prospects
• Towards the Minimum Inner Edge Distance of the Habitable Zone
• The 10 parsec sample in the Gaia era
• Habitable-zone super-Earth candidate in a six-planet system around the K2.5V star HD 40307
• Gaia DR3 astrometric orbit determination with Markov Chain Monte Carlo and Genetic Algorithms. Systems with stellar, substellar, and planetary mass companions
• Radial-Velocity Fitting Challenge. II. First results of the analysis of the data set
• Increased Tidal Dissipation Using Advanced Rheological Models: Implications for Io and Tidally Active Exoplanets
• The Anglo-Australian Planet Search. XXII. Two New Multi-Planet Systems
• Habitability of planets on eccentric orbits: the limits of the mean flux approximation
• The HARPS search for southern extra-solar planets XXXV. Super-Earths around the M-dwarf neighbors Gl433 and Gl667C
• Radial velocity signatures of Zeeman broadening
• GJ 832c: A super-earth in the habitable zone
• Bayesian analysis of radial velocity data of GJ667C with correlated noise: evidence for only 2 planets
• Radial Velocity Planet Detection Biases at the Stellar Rotational Period
• Disentangling Planets and Stellar Activity for Gliese 667C
• Miniature Exoplanet Radial Velocity Array (MINERVA) I. Design, Commissioning, and First Science Results
• Dynamical evolution and spin-orbit resonances of potentially habitable exoplanets. The case of GJ 581d
• The Hunt for Exomoons with Kepler (HEK): III. The First Search for an Exomoon around a Habitable-Zone Planet
• A Dynamical Analysis of the Proposed Circumbinary HW Virginis Planetary System
• On the Habitable Zones of Circumbinary Planetary Systems
• The Impact of Stellar Rotation on the Detectability of Habitable Planets Around M Dwarfs
• The habitable zone of Earth-like planets with different levels of atmospheric pressure
• An Independent Planet Search In The Kepler Dataset. II. An extremely low-density super-Earth mass planet around Kepler-87
• Radial Velocity Fitting Challenge. I. Simulating the data set including realistic stellar radial-velocity signals
• On the Stability of Super-Earth Atmospheres
• GJ 1214b revised. Improved trigonometric parallax, stellar parameters, orbital solution, and bulk properties for the super-Earth GJ 1214b
• Spectral features of Earth-like planets and their detectability at different orbital distances around F, G, and K-type stars
• A planetary system with gas giants and super-Earths around the nearby M dwarf GJ 676A. Optimizing data analysis techniques for the detection of multi-planetary systems
• A Detailed Analysis of the HD 73526 2:1 Resonant Planetary System
• Development of Fiber Fabry-Perot Interferometers as Stable Near-infrared Calibration Sources for High Resolution Spectrographs
• Resonant periodic orbits in the exoplanetary systems
• Calculating the Habitable Zone of Multiple Star Systems (http://astro.twam.info/hz)
• Two Super-Earths Orbiting the Solar Analogue HD41248 on the edge of a 7:5 Mean Motion Resonance
• The Dawes Review 3: The Atmospheres of Extrasolar Planets and Brown Dwarfs
• A Detailed Investigation of the Proposed NN Serpentis Planetary System
• Period and amplitude variations in post-common-envelope eclipsing binaries observed with SuperWASP
• No evidence of the planet orbiting the extremely metal-poor extragalactic star HIP13044
• A Hot Uranus Orbiting the Super Metal-rich Star HD77338 and the Metallicity - Mass Connection
• Up to four planets around the M dwarf GJ 163. Sensitivity of Bayesian planet detection criteria to prior choice
• Earth-like Habitats in Planetary Systems
• Characterization of potentially habitable planets: Retrieval of atmospheric and planetary properties from emission spectra
• Phase Variation of Earthshine Polarization Spectra
• K2-290: a warm Jupiter and a mini-Neptune in a triple-star system
• Two planetary companions around the K7 dwarf GJ 221 : a hot super-Earth and a candidate in the sub-Saturn desert range
• The Solar Neighborhood XXIX: The Habitable Real Estate of our Nearest Stellar Neighbors
• AD Leonis: Radial velocity signal of stellar rotation or spin-orbit resonance?
• Colors of extreme exo-Earth environments
• The test case of HD26965: difficulties disentangling weak Doppler signals from stellar activity
• The Formation and Dynamics of Super-Earth Planets
• TOI-132 b: A short-period planet in the Neptune desert transiting a $V=11.3$ G-type star
• The Lick-Carnegie Exoplanet Survey: Gliese 687b: A Neptune-Mass Planet Orbiting a Nearby Red Dwarf
• Search for exoplanet around northern circumpolar stars - Four planets around HD 11755, HD 12648, HD 24064, and 8 Ursae Minoris
• Planetary system around LTT 1445A unveiled by ESPRESSO: Multiple planets in a triple M-dwarf system
• Age Aspects of Habitability
• The effects of viewing angle on the mass distribution of exoplanets
• Co-spatial velocity and magnetic swirls in the simulated solar photosphere
• Improved signal detection algorithms for unevenly sampled data. Six signals in the radial velocity data for GJ876
• Atmospheric constraints for the CO2 partial pressure on terrestrial planets near the outer edge of the habitable zone
• Dynamical evolution and spin-orbit resonances of potentially habitable exoplanets. The case of GJ 667C
• Evolution of the habitable zone of low-mass stars. Detailed stellar models and analytical relationships for different masses and chemical compositions
• The CARMENES search for exoplanets around M dwarfs. A super-Earth planet orbiting HD 79211 (GJ 338 B)
• Large Interferometer For Exoplanets (LIFE). X. Detectability of currently known exoplanets and synergies with future IR/O/UV reflected-starlight imaging missions
• TOI-1842b: A Transiting Warm Saturn Undergoing Re-Inflation around an Evolving Subgiant
• Liquid Water on Cold Exo-Earths via Basal Melting of Ice Sheets
• In Situ Models for Planet Assembly around Cool stars
• Search for bright nearby M dwarfs with Virtual Observatory tools
• GJ 3929: High Precision Photometric and Doppler Characterization of an Exo-Venus and its Hot, Mini-Neptune-mass Companion
• The Impact of Stellar Abundance Variations on Stellar Habitable Zone Evolution
• A Method to Identify the Boundary Between Rocky and Gaseous Exoplanets from Tidal Theory and Transit Durations
• The Lick-Carnegie Survey: A New Two-Planet System Around the Star HD 207832
• An Early Catalog of Planet Hosting Multiple Star Systems of Order Three and Higher
• Can there be additional rocky planets in the Habitable Zone of tight binary stars with a known gas giant?
• TOI-1696 and TOI-2136: Constraining the Masses of Two Mini-Neptunes with HPF
• The Spin-Orbit Evolution of GJ 667C System: The Effect of Composition and Other Planet's Perturbations
• Correlating Intrinsic Stellar Parameters with Mg II Self-Reversal Depths
• Non-thermal motions and atmospheric heating of cool stars
• Planetary system architectures with low-mass inner planets: Direct imaging exploration of mature systems beyond 1 au
• Probing the Limits of Habitability: A Catalog of Rocky Exoplanets in the Habitable Zone
• Deriving Iodine-free spectra for high-resolution echelle spectrographs
• Destruction of "Peas in a Pod?" A Candidate Multi-planet System Around the Nearby, Bright Star, HD208487
• The Carina High-Contrast Imaging Project for massive Stars (CHIPS) I. Methodology and proof of concept on QZ Car ($\equiv$ HD93206)
• Asymmetry and Variability in the Transmission Spectra of Tidally Locked Habitable Planets