WASP-4 is a star with 0.86 times the mass of the Sun, and 0.89 times its radius. It is located 871.51 light years away from the solar system and is estimated to be 7 billion years old, as compared to the Sun which is roughly 4.6 billion years old.
WASP-4 is known to have 1 exoplanets in orbit around it.
WASP-4 b was discovered by the SuperWASP observatory, in 2008-03, using the transit method. Its semi-major axis is 0.02 astronomical units, as compared to Earth's which is 1 astronomical unit. The mass of WASP-4 b is 377.148 times the mass of Earth. The radius of WASP-4 b is 14.807 that of Earth. At more than 50 Earth masses, WASP-4 b is a gas giant, a planet whose mass is mostly made up of hydrogen and helium, like Jupiter and Saturn in our solar system.