HD 10180 c

HD 10180 c is an exoplanet approximately 130 light-years away in the constellation Hydrus. It was discovered in 2010 using the radial velocity method. With a minimum mass comparable to that of Neptune, it is of the class of planets known as Hot Neptunes. Dynamical simulations suggest that if the mass gradient was any more than a factor of two, the system would not be stable.
While planet c does not exist in any mean motion resonances, both planets with adjacent orbits share near resonances with c.