HD 154857: A Sun-Like Star with Two Giant Companions

HD 154857 is a star located 207 light-years from Earth. It is a G0 star, placing it in the same broad temperature class as the Sun, and it hosts two known planets. The star's reported radius estimate is larger than the Sun's, at 2.27 solar radii, while its reported temperature of 5600 K is cooler than the Sun's. Its mass is 0.99 solar masses.

The two planets were both found by 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 154857 b was discovered in 2004, and HD 154857 c was discovered in 2014.

HD 154857 b has a minimum mass of 779 Earth masses, a lower bound on its true mass, and an orbital period of 409 days. Its minimum mass is larger than Earth's and roughly 2.45 times Jupiter's mass. Among the listed planets, it has the shortest year by reported estimates, at 409 days, and the smallest minimum mass.

HD 154857 c has a minimum mass of 820 Earth masses, also a lower bound, and an orbital period of 3450 days. That minimum mass is larger than Earth's and roughly 2.58 times Jupiter's mass. Among the listed planets, HD 154857 c has the longest year by reported estimates, at 3450 days, and the largest minimum mass.