TOI-1749 and Its Three Planets

TOI-1749 is an M0 V star located 325 light-years away. Its spectral type marks it as a small, cool red dwarf. The star's reported mass estimate is 0.58 solar masses and its reported radius estimate is 0.55 solar radii, both smaller than the Sun's. Its reported temperature is 3990 K, cooler than the Sun's. It also has a reported lower limit of 0.8 billion years on its age. Three planets are known to orbit this host.

All three planets were discovered by transit in 2021, a method in which a planet passes in front of its star from our viewpoint and causes a small dip in observed brightness. Repeated dips help establish orbital periods. TOI-1749 b is classified as Earth-like, with a reported upper limit of 57 Earth masses and a radius of 1.39 Earth radii, larger than Earth's. Its orbital period is 2.39 days, the shortest year among the listed planets by reported estimates. TOI-1749 c is a Super-Earth with a reported upper limit of 14 Earth masses and a radius of 2.12 Earth radii, larger than Earth's. Its orbital period of 4.49 days is the second-shortest year among the listed planets by reported estimates. TOI-1749 d is Neptune-like, with a reported upper limit of 15 Earth masses and a radius of 2.52 Earth radii, larger than Earth's. Its orbital period is 9.05 days, the longest year among the listed planets by reported estimates. Among the listed planets, TOI-1749 b has the smallest radius and TOI-1749 d has the largest radius by reported estimates.