Under standard assumptions eccentricity -LRB- -RRB- is strictly defined for all circular , elliptic , parabolic and hyperbolic orbits and may take following values : for circular orbits : , for elliptic orbits : , for hyperbolic trajectories : .

Eccentricity -LRB- -RRB- is defined for all circular , elliptic , parabolic and hyperbolic orbits .
