75 Cet: A Giant Star with Two Known Worlds

75 Cet is a G3 III star located 271 light-years away. The "III" in its spectral type indicates it is a giant, a more evolved and luminous class than the Sun's. Its reported mass is 2.49 solar masses and its radius is 10.5 solar radii, both larger than the Sun's. Its temperature of 4850 K is cooler than the Sun's.

Two planets have been found orbiting this star. Both were detected by the radial velocity method, which measures the wobble a planet's gravity induces in its star's motion. The first, 75 Cet b, was reported in 2012. Its minimum mass is 788 Earth masses, roughly 2.48 times Jupiter's mass, and its orbital period is 697 days. The second, 75 Cet c, was reported in 2023. Its minimum mass is 290 Earth masses, and its orbital period is 2050 days. Among the listed planets, 75 Cet c has the smallest minimum mass and 75 Cet b has the largest minimum mass. 75 Cet b also has the shortest year among the listed planets, at 697 days, while 75 Cet c has the longest, at 2050 days.

The minimum masses indicate that both planets are at least as massive as the values quoted, though their true masses could be higher.