The number of multi-planet systems known to be orbiting their host stars with orbital periods that place them in mean motion resonances is growing .
For the most part , these systems are in first-order resonances and dynamical studies have focused their efforts towards understanding the origin and evolution of such dynamically resonant commensurabilities .
We report here the discovery of two super-Earths that are close to a second-order dynamical resonance , orbiting the metal-poor ( [ Fe/H ] =-0.43 dex ) and inactive G2V star HD41248 .
We analysed 62 HARPS archival radial velocities for this star , that until now , had exhibited no evidence for planetary companions .
Using our new Bayesian Doppler signal detection algorithm , we find two significant signals in the data , with periods of 18.357 days and 25.648 days , indicating they could be part of a 7:5 second-order mean motion resonance .
Both semi-amplitudes are below 3ms ^ { -1 } and the minimum masses of the pair are 12.3 and 8.6 M _ { \oplus } , respectively .
Our simulations found that apsidal alignment stabilizes the system , and even though libration of the resonant angles was not seen , the system is affected by the presence of the resonance and could yet occupy the 7:5 commensurability , which would be the first planetary configuration in such a dynamical resonance .
Given the multitude of low-mass multiplanet systems that will be discovered in the coming years , we expect more of these second-order resonant configurations will emerge from the data , highlighting the need for a better understanding of the dynamical interactions between forming planetesimals .