TOI-2000: A Distant Star With Two Known Worlds

TOI-2000 is a star located 573 light-years from Earth. It is a single-star system with two known planets. The star is 5.3 billion years old and has a mass of 1.08 solar masses, a radius of 1.13 solar radii, and a temperature of 5610 K. Its mass and radius are both larger than the Sun's, while its temperature is cooler.

Both planets were discovered in 2023 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-2000 b is a Neptune-like planet with a mass of 11 Earth masses, a radius of 2.7 Earth radii, and an orbital period of 3.1 days. Both its mass and radius are larger than Earth's, and its mean density is 3.08 g/cm³, or 0.559 times Earth's. Among the listed planets, it has the shortest year by reported estimates, the smallest radius, and the smallest reported mass.

TOI-2000 c is a Jupiter-like planet with a mass of 81.7 Earth masses, a radius of 8.14 Earth radii, and an orbital period of 9.13 days. Both its mass and radius are larger than Earth's, and its mean density is 0.835 g/cm³, or 0.151 times Earth's. Among the listed planets, it has the longest year by reported estimates, the largest radius, and the largest reported mass.