Gliese 667

Gliese 667 (142 G. Scorpii) is a triple-star system in the constellation Scorpius lying at a distance of about 7.2 parsecs (23 light-years) from Earth. All three of the stars have masses smaller than the Sun. To the naked eye, the system appears to be a single faint star of magnitude 5.89. The system has a relatively high proper motion, exceeding 1 second of arc per year. There is a 12th-magnitude star visually close to the other three, but it is a distant background star not gravitationally bound to the system. The two brightest stars in this system, GJ 667 A and GJ 667 B, are orbiting each other at an average angular separation of 1.81 arcseconds with a high eccentricity of 0.58. At the estimated distance of this system, this is equivalent to a physical separation of about 12.6 AU, or nearly 13 times the separation of the Earth from the Sun. Their eccentric orbit brings the pair as close as about 5 AU to each other, or as distant as 20 AU, corresponding to an eccentricity of 0.6. This orbit takes approximately 42.15 years to complete and the orbital plane is inclined at an angle of 128° to the line of sight from the Earth. The third star, GJ 667 C, orbits the GJ 667 AB pair at an angular separation of about 30", which equates to a minimum separation of 230 AU. GJ 667 C also has a system of two confirmed super-Earths and a number of additional doubtful candidates, though the innermost, GJ 667 Cb, may be a gas dwarf; GJ 667 Cc, and the controversial Cf and Ce, are in the circumstellar habitable zone.