16 Cygni B planet. Artwork of a Jupiter-like plan- et of the 16 Cygni B star system, with its moon (lower right). The moon is made of ice which heats up & vapourises to form a comet-like tail when the planet nears the stars. The system has three stars (at lower left), two are Sun-like and another is a red dwarf. The planet follows an eccentric path in its 2.2 year orbit. Compared to our own solar system its path stretches from within the orbit of Venus to far beyond that of Mars. The planet has about 1.5 times the mass of Jupiter, and was discovered in October 1996 by teams headed by G. Marcy, P. Butler, A.P. Hatzes & W.D. Cochran who measured its gravitational effect on the stars.