HD 147018 and Its Two Known Planets

HD 147018 is a G9 V star located 132 light-years away. Its spectral type places it among the G-type stars, the same broad temperature class as the Sun. The star is estimated to be 6.36 billion years old, with a reported mass of 0.927 solar masses, which is smaller than the Sun's mass. Its reported temperature, 5440 K, is cooler than the Sun's temperature.

Two planets are known to orbit HD 147018. Both were discovered in 2009 using the radial velocity method, which measures the wobble a planet's gravity induces in its star's motion; repeated wobbles reveal the planet and its orbital period.

HD 147018 b has a minimum mass of 674 Earth masses, meaning its true mass is at least this value. That minimum mass is larger than Earth's and roughly 2.12 times Jupiter's mass. The planet completes one orbit, its year, in 44.2 days. Among the listed planets, HD 147018 b has the shortest year by reported estimates and the smallest minimum mass.

HD 147018 c has a minimum mass of 2080 Earth masses, also a lower bound on its true mass. That minimum mass is larger than Earth's and roughly 6.54 times Jupiter's mass. Its orbital period is 1010 days. Among the listed planets, HD 147018 c has the longest year by reported estimates and the largest minimum mass.