HIP 55507 b: A Massive World Around a Small Red Dwarf

HIP 55507 is an M0 star, a small, cool red dwarf, located 83.1 light-years from the Sun. Its reported mass estimate is 0.65 solar masses and its reported radius estimate is 0.724 solar radii, both smaller than the Sun's. The star's reported temperature is 4170 K, cooler than the Sun's. One planet is known to orbit this host.

That planet, HIP 55507 b, was discovered in 2022 using the radial velocity method, which measures the wobble a planet's gravity induces in its star's motion; repeated wobbles reveal the planet and its orbital period. HIP 55507 b has a reported mass estimate of 2590 Earth masses, larger than Earth's and roughly 8.14 times Jupiter's mass. Its orbital period is 5140 days.