HD 23079 and Its Two Planets

HD 23079 is a star located 109 light-years away. Its spectral type is F9.5 V, placing it among the hotter, white-tinged stars on the main sequence. The star is 2.6 billion years old and holds 1.16 solar masses, with a radius of 1.08 solar radii and a temperature of 5990 K. Both its reported mass and radius estimates are larger than the Sun's, and its reported temperature is hotter as well.

Two planets are known to orbit this host. HD 23079 b was discovered in 2001 by the radial velocity method, which detects the wobble a planet's gravity induces in its star's motion; repeated wobbles reveal the planet and its orbital period. The planet has a minimum mass of 845 Earth masses, larger than Earth's and roughly 2.66 times Jupiter's mass. It completes one orbit every 736 days, the longest year among the listed planets.

HD 23079 c was discovered in 2025, also by radial velocity. Its minimum mass is 8.26 Earth masses, larger than Earth's and the smallest minimum mass among the listed planets. It orbits in just 5.75 days, giving it the shortest year of the two.

A minimum mass is a lower bound on a planet's true mass, distinct from an ordinary mass estimate. In this system, HD 23079 c is far lighter than HD 23079 b, while HD 23079 b's minimum mass stands at 845 Earth masses.