• DOI:10.1051/0004-6361/200912172
• Corpus ID: 2983930

The HARPS search for southern extra-solar planets: XVIII. An Earth-mass planet in the GJ 581 planetary system

@article{Mayor2009TheHS,
  title={The HARPS search for southern extra-solar planets: XVIII. An Earth-mass planet in the GJ 581 planetary system},
  author={Michel Mayor and Xavier Bonfils and Thierry Forveille and Xavier Delfosse and St{\'e}phane Udry and J L Bertaux and Herv'e Beust and François Bouchy and Cristophe Lovis and Francesco A. Pepe and Christian Perrier and Didier Queloz and Nuno C. Santos},
  journal={Astronomy and Astrophysics},
  year={2009},
  volume={507},
  pages={487-494}
}

• M. Mayor, X. Bonfils, +10 authors N. Santos
• Published 15 June 2009
• Physics, Geology
• Astronomy and Astrophysics

The GJ 581 planetary system was already known to harbour three planets, including two presumably rocky planets which straddle its habitable zone. We report here the detection of an additional planet ‐ GJ 581e ‐ with a minimum mass of 1.9 M" . With a period of 3.15 days, it is the innermost planet of the system and has a # 5% transit probability. We also correct our previous confusion of the orbital period of GJ 581d (the outermost planet) with a one-year alias, thanks to an extended time span and many more measurements. The revised period is 66.8 days, and locates the semi-major axis inside the habitable zone of the low mass star. The dynamical stability of the 4-planet system imposes an upper bound on the orbital plane inclination. The planets cannot be more massive than approximately 1.6 times their minimum mass.