We study the orbital architecture , physical characteristics of planets , formation and long-term evolution of the Kepler-30 planetary system , detected and announced in 2012 by the Kepler team .
We show that the Kepler-30 system belongs to a particular class of very compact and quasi-resonant , yet long-term stable planetary systems .
We re-analyse the light curves of the host star spanning Q1-Q17 quarters of the Kepler mission .
A huge variability of the Transit Timing Variations ( TTV ) exceeding 2 days is induced by a massive Jovian planet located between two Neptune-like companions .
The innermost pair is near to the 2:1 mean motion resonance ( MMR ) , and the outermost pair is close to higher order MMRs , such as 17:7 and 7:3 .
Our re-analysis of photometric data allows us to constrain , better than before , the orbital elements , planets ’ radii and masses , which are 9.2 \pm 0.1 , 536 \pm 5 , and 23.7 \pm 1.3 Earth masses for Kepler-30b , Kepler-30c and Kepler-30d , respectively .
The masses of the inner planets are determined within \sim 1 \% uncertainty .
We infer the internal structures of the Kepler-30 planets and their bulk densities in a wide range from ( 0.19 \pm 0.01 ) g \cdot cm ^ { -3 } for Kepler-30d , ( 0.96 \pm 0.15 ) g \cdot cm ^ { -3 } for Kepler-30b , to ( 1.71 \pm 0.13 ) g \cdot cm ^ { -3 } for the Jovian planet Kepler-30c .
We attempt to explain the origin of this unique planetary system and a deviation of the orbits from exact MMRs through the planetary migration scenario .
We anticipate that the Jupiter-like planet plays an important role in determining the present dynamical state of this system .