16 Cygni

16 Cygni is a triple star system located approximately 70 light-years away in the constellation Cygnus. The system consists of two Sun-like stars, 16 Cygni A and 16 Cygni B, and a red dwarf star, 16 Cygni C.

16 Cygni A (HD 204760) is a G1.5 V star, slightly more massive and hotter than the Sun. It is notable for hosting an extrasolar planet, 16 Cygni Bb, discovered in 1996. This planet is a gas giant with a highly eccentric orbit, meaning its distance from 16 Cygni A varies considerably throughout its orbit. This eccentricity has made 16 Cygni Bb a subject of much study and debate regarding planetary formation and orbital dynamics.

16 Cygni B (HD 204759) is a G3 V star, nearly identical to the Sun in mass and temperature. It is located relatively far from 16 Cygni A, at a distance of approximately 73 arcseconds. The considerable distance between the two stars suggests that their gravitational interaction is relatively weak.

16 Cygni C is a red dwarf star significantly fainter and less massive than the other two stars in the system. Its precise orbital characteristics and influence on the overall system are less well-understood compared to A and B due to its faintness and greater distance.

The system as a whole is valuable for studying stellar and planetary evolution in a multi-star environment. The presence of a planet with an eccentric orbit around 16 Cygni A challenges traditional models of planet formation and migration. The system continues to be a focus of ongoing astronomical research.