TOI-756: A Nearby Red Dwarf with Two Known Planets

TOI-756 is an M1 V star, a small, cool red dwarf, located 281 light-years from Earth. Its age is 3.2 billion years, with a mass of 0.505 solar masses and a radius of 0.505 solar radii. Its reported temperature is 3660 K, cooler than the Sun's. Hosting two known planets, the system includes one world discovered by the transit method and one by radial velocity, both first reported in 2025.

TOI-756 b is a Neptune-like planet with a radius of 2.81 Earth radii, larger than Earth's, and a mass of 9.83 Earth masses, also larger than Earth's. Its mean density is 2.44 g/cm³, or 0.443 times Earth's. It completes an orbit every 1.24 days, giving it the shortest year among the listed planets.

TOI-756 c was detected through radial velocity measurements, which track the wobble a planet's gravity induces in its star's motion. Its period is 149 days, the longest among these two planets, and its minimum mass is 1290 Earth masses - a lower bound on its true mass. This minimum mass is larger than Earth's and roughly 4.05 times Jupiter's mass.