TOI-2141: A Nearby Star with Three Known Worlds

TOI-2141 is a star 253 light-years from us with three planets orbiting it. It has an age of 6.4 billion years, a mass of 0.94 solar masses, a radius of 0.98 solar radii, and a temperature of 5660 K. Its mass is smaller than the Sun's, and its temperature is cooler than the Sun's.

Three planets are known around TOI-2141. TOI-2141 b, a Neptune-like planet discovered by transit in 2023, has a mass of 20.1 Earth masses and a radius of 3.15 Earth radii. Its orbital period is 18.3 days, making it the second-shortest year among the listed planets. Its mean density is 3.55 g/cm³, 0.645 times Earth's.

TOI-2141 c and TOI-2141 d were both discovered by radial velocity in 2025. The radial velocity method measures the wobble a planet's gravity induces in its star's motion. TOI-2141 c has a minimum mass of 6.14 Earth masses and an orbital period of 5.46 days, the shortest year among the listed planets. TOI-2141 d has a minimum mass of 14.9 Earth masses and an orbital period of 60.5 days, the longest year among the listed planets. Both minimum masses are lower bounds on the planets' true masses.