Using the stellar mass and period, he calculated semimajor axis as 0.911 astronomical units.

So this planet will need couple more years of observations to better constrain the period and semimajor axis.

However, as the semimajor axis of the Moon's orbit continues to increase in the future, this stabilizing effect will diminish.

Geodesists, by convention, use the semimajor axis and flattening.

They orbit each other with an estimated period of 201 years and a semimajor axis of 0.45 arcseconds.

From the geometry of an ellipse, where a is the length of the semimajor axis.

The parameters for this planet are poorly constrained, including mass, semimajor axis, and orbital period.

It differs from the sidereal period because the object's semimajor axis typically advances slowly.

Its semimajor axis is 2.54 AU placing just outside the star's habitable zone.

The boundary for the semimajor axis is surprisingly sharp for the prograde satellites.

Dione orbits Saturn with a semimajor axis about 2 percent less than that of Earth's moon.

The secondary star B orbits A at only 9.5 times the semimajor axis of A's planet.

The eccentricity is also the ratio of the semimajor axis a to the distance d from the center to the directrix:

Semimajor axis () - the sum of the periapsis and apoapsis distances divided by two.

Semimajor axis ()

Where and are the semimajor axes of the two elliptical transfer orbits and are given by:

For example, such a mechanism can produce sungrazing comets, because a large eccentricity with a constant semimajor axis results in a small perihelion.

The eccentricity can be defined as the ratio of the linear eccentricity to the semimajor axis a: that is, .

Just about exactly; the semimajor axis of Pluto's orbit is thirty-nine A.U. and change."

The orbit's semimajor axis puts the planet in the habitable zone of Upsilon Andromedae A.

An asteroid family is a population of asteroids that share similar proper orbital elements, such as semimajor axis, eccentricity, and orbital inclination.

Such stellar component could likely take 42.4 years to complete its orbit around the Cepheid (semimajor axis around 10.8 Astronomical Units).

It shows a noticeable amount of flattening, with an aspect ratio of 0.62 0.23 between its semimajor axis and semiminor axis.

In the following, a is the larger dimension (e.g. semimajor axis), while b is the smaller (semiminor axis).

The resulting irregular orbits match well with the observed populations' semimajor axes, inclinations and eccentricities, but not with their size distribution.