LTT 1445 A and Its Two Known Planets

LTT 1445 A is an M3.0 star located 22.4 light-years away. Its spectral type marks it as a cool, red dwarf. The star has a reported mass estimate of 0.257 solar masses and a reported radius estimate of 0.265 solar radii, both smaller than the Sun's. Its reported temperature is 3340 K, cooler than the Sun's.

Two planets are known to orbit this host. Both were found by the transit method, in which a planet crosses in front of its star from our viewpoint and causes a small dip in observed brightness. LTT 1445 A b was discovered in 2019. It is an Earth-like planet, a size class that stays within 1.5 times Earth's radius. Its reported radius estimate is 1.34 Earth radii, larger than Earth's, and its reported mass estimate is 2.73 Earth masses, also larger than Earth's. Its mean density is 6.25 g/cm³, 1.13 times Earth's. It completes an orbit, or year, in 5.36 days. Among the listed planets, it has the longest year by reported estimates and the largest radius and reported mass.

LTT 1445 A c was discovered in 2022 and is also Earth-like. Its reported radius estimate is 1.15 Earth radii, larger than Earth's, and its reported mass estimate is 1.54 Earth masses, larger than Earth's. Its mean density is 5.62 g/cm³, 1.02 times Earth's. Its orbital period is 3.12 days. Among the listed planets, it has the shortest year by reported estimates and the smallest radius and reported mass.