TOI-4311: A K-Type Star with Two Transiting Worlds

TOI-4311 is a K-type star located 440 light-years away, with a reported age of 6.6 billion years. Its mass is 0.816 solar masses, its radius is 0.844 solar radii, and its temperature is 5060 K. The star's reported mass estimate is smaller than the Sun's, its reported radius estimate is smaller than the Sun's, and its reported temperature is cooler than the Sun's. Two planets are known to orbit it, both discovered in 2026 by the transit method, in which a planet passing in front of its star from our viewpoint causes a small dip in observed brightness.

TOI-4311 b is classified as Earth-like and has a mass of 4.5 Earth masses and a radius of 1.38 Earth radii, both larger than Earth's. Its mean density is 9.52 g/cm³, 1.73 times Earth's. It completes an orbit in 0.99 days, the shortest orbital period among the listed planets, and has the smallest radius among them.

TOI-4311 c is a Super-Earth with a reported upper limit of 13.58 Earth masses, a bound rather than an exact value, and a radius of 2.47 Earth radii, larger than Earth's. It orbits in 15.1 days, the longest orbital period among the listed planets, and has the largest radius among them.