Orbital period

periodsynodic periodsynodicsidereal periodsynodalsynodic cycleorbitingorbitsperiodsP
The orbital period is the time a given astronomical object takes to complete one orbit around another object, and applies in astronomy usually to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars.wikipedia
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Orbital resonance

1:1 resonanceresonancemean-motion resonance
Such variations also include the true placement of the centre of gravity between two astronomical bodies (barycenter), perturbations by other planets or bodies, orbital resonance, general relativity, etc. Most are investigated by detailed complex astronomical theories using celestial mechanics using precise positional observations of celestial objects via astrometry.
In celestial mechanics, orbital resonance occurs when orbiting bodies exert regular, periodic gravitational influence on each other, usually because their orbital periods are related by a ratio of small integers.

Exoplanet

extrasolar planetexoplanetsplanet
The orbital period is the time a given astronomical object takes to complete one orbit around another object, and applies in astronomy usually to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars.
In the 1890s, Thomas J. J. See of the University of Chicago and the United States Naval Observatory stated that the orbital anomalies proved the existence of a dark body in the 70 Ophiuchi system with a 36-year period around one of the stars.

Binary star

spectroscopic binaryeclipsing binarybinary
The orbital period is the time a given astronomical object takes to complete one orbit around another object, and applies in astronomy usually to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars.
Orbital periods can be less than an hour (for AM CVn stars), or a few days (components of Beta Lyrae), but also hundreds of thousands of years (Proxima Centauri around Alpha Centauri AB).

Nodal period

This type of orbital period applies to artificial satellites, like those that monitor weather on Earth, and natural satellites like the Moon.

Orbit

orbitsorbital motionplanetary motion
The orbital period is the time a given astronomical object takes to complete one orbit around another object, and applies in astronomy usually to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars.
A small radial impulse given to a body in orbit changes the eccentricity, but not the orbital period (to first order).

Year

myaMay
A year is the orbital period of the Earth moving in its orbit around the Sun.

Jupiter

JovianGioveplanet Jupiter
For example, Jupiter has a sidereal period of 11.86 years while the main binary star Alpha Centauri AB has a period of about 79.91 years.
Earth overtakes Jupiter every 398.9 days as it orbits the Sun, a duration called the synodic period.

Axial tilt

obliquityobliquity of the eclipticaxis
Over the course of an orbital period, the obliquity usually does not change considerably, and the orientation of the axis remains the same relative to the background of stars.

Moon

lunarthe MoonLuna
The Moon makes a complete orbit around Earth with respect to the fixed stars about once every 27.3 days (its sidereal period).

Planet

planetsFormer classification of planetsplanemo
The orbital period is the time a given astronomical object takes to complete one orbit around another object, and applies in astronomy usually to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars.
The period of one revolution of a planet's orbit is known as its sidereal period or year.

General relativity

general theory of relativitygeneral relativity theoryrelativity
Such variations also include the true placement of the centre of gravity between two astronomical bodies (barycenter), perturbations by other planets or bodies, orbital resonance, general relativity, etc. Most are investigated by detailed complex astronomical theories using celestial mechanics using precise positional observations of celestial objects via astrometry.

Kepler's laws of planetary motion

Kepler's third lawKepler's lawslaws of planetary motion
According to Kepler's Third Law, the orbital period T (in seconds) of two point masses orbiting each other in a circular or elliptic orbit is:

Mercury (planet)

MercuryMercurioplanet Mercury
Mercury with 5,427 kg/m 3 and Venus with 5,243 kg/m 3 ) we get:
The planet telescopically displays the complete range of phases, similar to Venus and the Moon, as it moves in its inner orbit relative to Earth, which recurs over its synodic period of approximately 116 days.

Elliptic orbit

elliptical orbitellipticalelliptic
According to Kepler's Third Law, the orbital period T (in seconds) of two point masses orbiting each other in a circular or elliptic orbit is:
In a gravitational two-body problem with negative energy, both bodies follow similar elliptic orbits with the same orbital period around their common barycenter.

Semi-major and semi-minor axes

semi-major axissemimajor axissemi-major axes
In astrodynamics the orbital period T of a small body orbiting a central body in a circular or elliptical orbit is:

Perturbation (astronomy)

perturbationsperturbationperturbed
Such variations also include the true placement of the centre of gravity between two astronomical bodies (barycenter), perturbations by other planets or bodies, orbital resonance, general relativity, etc. Most are investigated by detailed complex astronomical theories using celestial mechanics using precise positional observations of celestial objects via astrometry.
For example, in April 1996, Jupiter's gravitational influence caused the period of Comet Hale–Bopp's orbit to decrease from 4,206 to 2,380 years, a change that will not revert on any periodic basis.

Ceres (dwarf planet)

Ceres1 CeresAtmosphere of Ceres
From Earth, the apparent magnitude of Ceres ranges from 6.7 to 9.3, peaking once at opposition every 15 to 16 months, which is its synodic period.

Geostationary orbit

GeostationaryGEOgeostationary satellite
An object in such an orbit has an orbital period equal to the Earth's rotational period, one sidereal day, and so to ground observers it appears motionless, in a fixed position in the sky.

Proxima Centauri

Alpha Centauri Cits host starProxima
Currently it has a physical separation of about 12950 AU from AB and an orbital period of 550,000 years.

Rotation period

periodrotational periodrotates
It differs from the object's solar day, which may include an extra fractional rotation needed to accommodate the portion of the object's orbital period during one day.

List of periodic comets

periodicperiodic cometperiodic comets
Periodic comets (also known as short-period comets) are comets with orbital periods of less than 200 years or that have been observed during more than a single perihelion passage (e.g. 153P/Ikeya–Zhang).

Sidereal year

siderealEarth's orbital frequencySidereal orbital period

Deimos (moon)

DeimosDeimos moonMars II
For example, Deimos's synodic period is 1.2648 days, 0.18% longer than Deimos's sidereal period of 1.2624 d.
With a small telescope, a Martian observer could see Deimos's phases, which take 1.2648 days (Deimos's synodic period) to run their course.

Standard gravitational parameter

gravitational parametergeocentric gravitational constantheliocentric gravitational constant
: where r is the orbit radius, v is the orbital speed, ω is the angular speed, and T is the orbital period.

90377 Sedna

Sednarecently discovered dwarf planet
Sedna has the second longest orbital period of any known object in the Solar System of comparable size or larger, calculated at around 11,400 years.