WASP-17b is an exoplanet in the constellation Scorpius that is orbiting the star WASP-17. Its discovery was announced on 11 August 2009. It is the first planet discovered to have a retrograde orbit, meaning it orbits in a direction counter to the rotation of its host star. This discovery challenged traditional planetary formation theory. In terms of diameter, WASP-17b is one of the largest exoplanets discovered and which is only half the mass of Jupiter. Therefore it is the 8th place from our tops.
TrES-4b is an extrasolar planet, and one of the largest exoplanets ever found. It was discovered in 2006, and announced in 2007, by the Trans-Atlantic Exoplanet Survey, using the transit method. It is approximately 1,400 light-years (430 pc) orbiting the star GSC 02620-00648, in the constellation Hercules. TrES-4 orbits its primary star every 3.543 days and eclipses it when viewed from Earth. The planet is 0.919 times as big as Jupiter but 1.799 times the diameter. The largest exoplanet ever found at the time giving it an average density of only about 0.333 grams per cubic centimeter, approximately the same as Saturn’s moon Methone.