HD 48948 and Its Three Known Planets

HD 48948 is a K3 V star located 55.1 light-years away. Its spectral type identifies it as a K-type main-sequence dwarf, a star cooler and redder than the Sun. The star's reported mass estimate is smaller than the Sun's, at 0.686 solar masses, and its reported radius estimate is also smaller than the Sun's, at 0.679 solar radii. Its reported temperature is cooler than the Sun's, at 4590 K. The star's age is 11.5 billion years.

Three planets are known to orbit HD 48948: HD 48948 b, HD 48948 c, and HD 48948 d. All three were discovered in 2024 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.

Each planet has a minimum mass, a lower bound on its true mass. HD 48948 b has a minimum mass of 4.88 Earth masses and an orbital period of 7.34 days. HD 48948 c has a minimum mass of 7.27 Earth masses and an orbital period of 38.1 days. HD 48948 d has a minimum mass of 10.6 Earth masses and an orbital period of 152 days. Among the listed planets, HD 48948 b has the shortest year by reported estimates, at 7.34 days, while HD 48948 d has the longest, at 152 days. HD 48948 c has the second-shortest year by reported estimates, at 38.1 days. Among the listed planets, HD 48948 b also has the smallest minimum mass, at 4.88 Earth masses, while HD 48948 d has the largest, at 10.6 Earth masses. HD 48948 c has the second-smallest minimum mass, at 7.27 Earth masses. The minimum mass of each of the three planets is larger than Earth's.