Gliese 667 Cc orbits which star in a triple-star system?

Gliese 667 Cc orbits Gliese 667 C, the small red-dwarf star in the Gliese 667 triple-star system.

Gliese 667 C is the least massive member of the system; the larger stars Gliese 667 A and B form a widely separated pair, while C orbits that pair at roughly 230 astronomical units. The planet’s host is therefore not the entire triple system but specifically the M-type star designated Gliese 667 C.

Gliese 667 Cc was identified using the radial-velocity method, which detects the gravitational wobble a planet induces in its star. It was first reported in 2011 and formally announced in 2012. The planet circles its red-dwarf host every 28.155 Earth days at a distance of about 0.125 astronomical units.

Its location in the star’s habitable zone made it a widely discussed potentially habitable super-Earth. However, “potentially habitable” does not establish life or even a surface suitable for life; atmospheric conditions, tidal effects, and the planet’s true composition remain uncertain. The letter C in both names is the key clue: Cc means a planet around star C.