51 Peg is a star with 1.03 times the mass of the Sun, and 1.18 times its radius. It is located 50.43 light years away from the solar system and is estimated to be 10 billion years old, as compared to the Sun which is roughly 4.6 billion years old.
51 Peg is known to have 1 exoplanets in orbit around it.
51 Peg b was discovered by the Haute-Provence Observatory observatory, in 1995-11, using the radial velocity method. Its semi-major axis is 0.05 astronomical units, as compared to Earth's which is 1 astronomical unit. The mass of 51 Peg b is 146.280 times the mass of Earth. The radius of 51 Peg b is 14.300 that of Earth. At more than 50 Earth masses, 51 Peg 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.