Following the recent discovery of the first radial velocity planet in a star still possessing a protoplanetary disc ( CI Tau ) , we examine the origin of the planet ’ s eccentricity ( e \sim 0.3 ) .
We show through long timescale ( 10 ^ { 5 } orbits ) simulations that the planetary eccentricity can be pumped by the disc , even when its local surface density is well below the threshold previously derived from short timescale integrations .
We show that the disc may be able to excite the planet ’ s orbital eccentricity in < a Myr for the system parameters of CI Tau .
We also perform two planet scattering experiments and show that alternatively the observed planet may plausibly have acquired its eccentricity through dynamical scattering of a migrating lower mass planet , which has either been ejected from the system or swallowed by the central star .
In the latter case the present location and eccentricity of the observed planet can be recovered if it was previously stalled within the disc ’ s magnetospheric cavity .