The HARPS search for southern extra-solar planets XI. Super-Earths (5 & 8 M_Earth) in a 3-planet system

Abstract

This Letter reports on the detection of two super-Earth planets in the Gl581 system, already known to harbour a hot Neptune. One of the planets has a mass of 5 M_Earth and resides at the ``warm'' edge of the habitable zone of the star. It is thus the known exoplanet which most resembles our own Earth. The other planet has a 7.7 M_Earth mass and orbits at 0.25 AU from the star, close to the ``cold'' edge of the habitable zone. These two new light planets around an M3 dwarf further confirm the formerly tentative statistical trend for i) many more very low-mass planets being found around M dwarfs than around solar-type stars and ii) low-mass planets outnumbering Jovian planets around M dwarfs.

Revised version resubmitted to A&A Letters, 5 pages, 4 figures

Cited by in corpus (52)

• Mass-Radius Relationships for Solid Exoplanets
• Habitable Zones Around Main-Sequence Stars: Dependence on Planetary Mass
• Habitable planets around the star Gl 581?
• A laser frequency comb that enables radial velocity measurements with a precision of 1 cm s${}^{-1}$
• Radial velocity planets de-aliased. A new, short period for Super-Earth 55 Cnc e
• Stellar Activity Masquerading as Planets in the Habitable Zone of the M dwarf Gliese 581
• An Earth-sized Planet in the Habitable Zone of a Cool Star
• A decreased probability of habitable planet formation around low-mass stars
• Planets Around Low-Mass Stars (PALMS). IV. The Outer Architecture of M Dwarf Planetary Systems
• Tidal Heating of Extra-Solar Planets
• Bayesian search for low-mass planets around nearby M dwarfs. Estimates for occurrence rate based on global detectability statistics
• Observable Consequences of Planet Formation Models in Systems with Close-in Terrestrial Planets
• Accurate Spitzer infrared radius measurement for the hot Neptune GJ 436b
• BANYAN. IV. Fundamental parameters of low-mass star candidates in nearby young stellar kinematic groups - Isochronal Age determination using Magnetic evolutionary models
• Is Gliese 581d habitable? Some constraints from radiative-convective climate modeling
• The impact of red noise in radial velocity planet searches: Only three planets orbiting GJ581?
• Tides and the Evolution of Planetary Habitability
• UV habitable zones around M stars
• DARWIN - A Mission to Detect, and Search for Life on, Extrasolar Planets
• Identifying the rotation rate and the presence of dynamic weather on extrasolar Earth-like planets from photometric observations
• The Collision Between The Milky Way And Andromeda
• A Search for Multi-Planet Systems Using the Hobby-Eberly Telescope
• Habitable Climates
• 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
• A ~5 M_earth Super-Earth Orbiting GJ 436?: The Power of Near-Grazing Transits
• A Jupiter-like Planet Orbiting the Nearby M Dwarf GJ832
• Dynamical evolution and spin-orbit resonances of potentially habitable exoplanets. The case of GJ 581d
• Formation, tidal evolution and habitability of the Kepler-186 system
• On the protection of extrasolar Earth-like planets around K/M stars against galactic cosmic rays
• Correlations between the stellar, planetary and debris components of exoplanet systems observed by $\text{Herschel}$
• New Worlds on the Horizon: Earth-Sized Planets Close to Other Stars
• An m sin i = 24 Earth Mass Planetary Companion To The Nearby M Dwarf GJ 176
• The HADES RV Programme with HARPS-N@TNG II. Data treatment and simulations
• Deep MMT Transit Survey of the Open Cluster M37 IV: Limit on the Fraction of Stars With Planets as Small as 0.3 R_J
• Exomoons in the habitable zones of M dwarfs
• Measuring the Galactic Distribution of Transiting Planets with WFIRST
• On the growth and stability of Trojan planets
• A secular theory of coplanar, non-resonant planetary system
• Composition of Ices in Low-Mass Extrasolar Planets
• Toward detection of terrestrial planets in the habitable zone of our closest neighbor: Proxima Centauri
• Spin evolution of Earth-sized exoplanets, including atmospheric tides and core-mantle friction
• Further Constraints on the Presence of a Debris Disk in the Multiplanet System Gliese 876
• Limits on additional planetary companions to OGLE-2005-BLG-390L
• Response to Comment on "Stellar activity masquerading as planets in the habitable zone of the M dwarf Gliese 581"
• Geothermal heating enhances atmospheric asymmetries on synchronously rotating planets
• Terrestrial Planets Formation under Migration: the Systems near 4:2:1 Mean Motion Resonance
• Two Jupiter-Mass Planets Orbiting HD 154672 and HD 205739
• Phyllosilicate Emission from Protoplanetary Disks: Is the Indirect Detection of Extrasolar Water Possible?
• Temporal changes of the flare activity of Proxima Cen
• Terrestrial Planet Formation in Extra-Solar Planetary Systems
• Stellar activity and magnetic shielding
• A Ride to Exoplanets: Finding Potentially Habitable Worlds