HD 59686 Ab is an exoplanet that orbits the giant starHD 59686 A in a close binary star system. It has a nearly circular orbit with a period of 300 days and a semi-major axis of 1.09 AU, slightly greater than the distance between Earth and the Sun. It has a minimum mass 6.9 times that of Jupiter, with the true mass depending on the orbital inclination, which is not yet known.[2] HD 59686 Ab was discovered by radial velocity and first announced in November 2003,[1] but the discovery was not formally published until 2016.[2]
HD 59686, along with Nu Octantis, is one of the closest binary star systems known to host a planet orbiting a single star (i.e., not a circumbinary planet), posing a challenge to theories of planet formation.[2]
