HD 188753 planetary system. Artwork of a view from a moon of the gas giant planet that orbits the primary star of the triple star system HD 188753. The primary star (A) is not seen, but the other two stars of HD 188753 (which form a binary star system called B) are seen on the horizon at lower left. The existence of this gas giant planet was inferred from gravitational wobbles of the primary star (A). The discovery was announced in July 2005 by Maciej Konacki of Caltech, USA. The planet orbits its star in 3.35 days, and has a mass at least 1.14 times that of Jupiter. Several gas giant planets have now been discovered orbiting nearby stars.