\textcolor blackI report the discovery of non-transiting close companions to two transiting warm Jupiters ( WJs ) , Kepler-448/KOI-12b ( orbital period P = 17.9 \mathrm { days } , radius R _ { p } = 1.23 ^ { +0.06 } _ { -0.05 } R _ { Jup } ) and Kepler-693/KOI-824b ( P = 15.4 \mathrm { days } , R _ { p } = 0.91 \pm 0.05 R _ { Jup } ) , via dynamical modeling of their transit timing and duration variations ( TTVs and TDVs ) .
The companions have masses of 22 ^ { +7 } _ { -5 } M _ { \mathrm { Jup } } ( Kepler-448c ) and 150 ^ { +60 } _ { -40 } M _ { \mathrm { Jup } } ( Kepler-693c ) , and both are on eccentric orbits ( e = 0.65 ^ { +0.13 } _ { -0.09 } for Kepler-448c and e = 0.47 ^ { +0.11 } _ { -0.06 } for Kepler-693c ) with periastron distances of 1.5 \mathrm { au } .
Moderate eccentricities are detected for the inner orbits as well ( e = 0.34 ^ { +0.08 } _ { -0.07 } for Kepler-448b and e = 0.2 ^ { +0.2 } _ { -0.1 } for Kepler-693b ) .
In the Kepler-693 system , a large mutual inclination between the inner and outer orbits ( 53 ^ { +7 } _ { -9 } \mathrm { deg } or 134 ^ { +11 } _ { -10 } \mathrm { deg } ) is also revealed by the TDVs .
This is likely to induce a secular oscillation of the inner WJ ’ s eccentricity that brings its periastron close enough to the host star for tidal star–planet interactions to be significant .
In the Kepler-448 system , the mutual inclination is weakly constrained and such an eccentricity oscillation is possible for a fraction of the solutions .
Thus these WJs may be undergoing tidal migration to become hot Jupiters ( HJs ) , although the migration via this process from beyond the snow line is disfavored by the close-in and massive nature of the companions .
This may indicate that WJs can be formed in situ and could even evolve into HJs via high-eccentricity migration inside the snow line .