HD 205739 b has a mildly elliptical orbit, given its orbital eccentricity of 0.27.
According to the Extrasolar Planets Encyclopaedia, which calculated Kepler-14b's eccentricity independently, Kepler-14b has a slightly irregular orbit, with an orbital eccentricity of 0.035.
The change of orbital eccentricity in an orbit around the host planet is given by (Delta e approx langle dot e rangle T_{mathrm {K}}).
Oberon's orbit has a small orbital eccentricity and inclination relative to the equator of Uranus.
After the initial ESRO program was initiated, the agency moved towards satellites with a higher orbital eccentricity and escape orbits.
The ancient Greek astronomers, Hipparchus and Ptolemy, had noted several periodic variations in the Moon's orbit, such as small oscillations in its orbital eccentricity and the inclination of its orbit to the plane of the ecliptic.
The Earth-induced component arises from libration, a result of the Moon's orbital eccentricity; if the Moon's orbit were perfectly circular, there would only be solar tides.
The scientists who worked on the paper discussed the role of orbital eccentricity, or how elliptical an orbit is, and how poorly constrained it tends to be amongst Hot Jupiters, where a circular orbit is assumed.
The best fit for the shape of HAT-P-33b's orbit suggests that the orbit is slightly elliptical, as the planet's orbital eccentricity is fit to 0.148.
It has an orbital eccentricity of 0.08, meaning that its orbit is very circular.
In comparison, planet Mercury lies 0.387 AU from the Sun, orbits every 87.97 days, and has an orbital eccentricity of 0.2056.
