HD 10180 and Its Six Planets

HD 10180 is a G1 V star located 127 light-years away. Its spectral type marks it as a Sun-like, main-sequence dwarf. The star is estimated to be 4.3 billion years old, with a mass of 1.06 solar masses and a temperature of 5910 K. Its reported mass estimate is larger than the Sun's, and its reported temperature is hotter than the Sun's. Six planets are known to orbit this star.

All six were discovered in 2010 using the radial velocity method. HD 10180 c has a minimum mass of 13.2 Earth masses and an orbital period of 5.76 days. HD 10180 d has a minimum mass of 12 Earth masses and a period of 16.4 days. HD 10180 e has a minimum mass of 25.6 Earth masses and a period of 49.7 days. HD 10180 f has a minimum mass of 22.9 Earth masses and a period of 123 days. HD 10180 g has a minimum mass of 23.3 Earth masses and a period of 605 days. HD 10180 h has a minimum mass of 65.7 Earth masses and a period of 2210 days.

Every planet's minimum mass is larger than Earth's. Among the listed planets, HD 10180 c has the shortest year by reported estimates, at 5.76 days, while HD 10180 d has the second-shortest, at 16.4 days. At the other end, HD 10180 h has the longest year by reported estimates, at 2210 days, and HD 10180 g has the second-longest, at 605 days. Among the listed planets, HD 10180 d has the smallest minimum mass, at 12 Earth masses, and HD 10180 c has the second-smallest, at 13.2 Earth masses. HD 10180 h has the largest minimum mass, at 65.7 Earth masses, and HD 10180 e has the second-largest, at 25.6 Earth masses. HD 10180 h's year of 2210 days is the longest among the six.