HD 10180 is a solar-type star that scientists believe has at least five planets, and possibly as many as seven. It is 127 light-years away, in the southern constellation of Hydrus. The mass and metallicity of HD 10180 are 6% and 20% greater than the values of the Sun.
The system contains five Neptune-sized planets (with minimum masses from 12 to 25 times Earth's; spurious detection probabilities ≪ 0.1%) at orbital radii of 0.06, 0.13, 0.27, 0.49 and 1.42 AU. In addition, there is a possible Earth-sized planet located at 0.02 AU (minimum mass 1.4 times Earth's; spurious detection probability 1.4%), and a possible Saturn-sized planet at 3.4 AU (minimum mass 65 times Earth's; spurious detection probability 0.6%). This represents the largest number of planets detected in an extrasolar planetary system (the previous record holder, the 55 Cancri system, has five).