Of or relating to two or more celestial bodies that share, or almost share, the same orbit.
Fr.: mouvement co-orbital
The motion of two or more bodies around the Sun on different orbits when it takes them the same amount of time to complete one revolution. There are three possible types of co-orbital motions of a small body associated with a planet: → tadpole orbits, → horseshoe orbits, and → quasi-satellite orbits.
→ co-orbital; → motion.
mâhvâre-ye ham-madâr, bandevâr-e ~
Fr.: satellite co-orbital
Any of satellites which either share the same orbit or which occupy immediately adjacent orbits that change periodically as the satellites approach one another (Ellis et al., 2007, Planetary Ring Systems, Springer).
→ co-orbital; → satellite.
Keplerian orbital velocity
tondâ-ye madâr-e Kepleri
Fr.: vitesse d'orbite képlérienne
The velocity of an object orbiting another object according to → Kepler's laws.
lunar sidereal orbital period
dowre-ye madâri-ye axtari-ye mâng
Fr.: période orbitale sidérale de la Lune
Same as → sidereal month.
1) madâri; 2) madârâl
Fr.: 1) orbital; 2) orbitale
1) Of or relating to an orbit.
orbital angular momentum
jonbâk-e zâviyeyi-ye madâri
Fr.: moment cinétique orbital, ~ angulaire ~
1) Mechanics: The → angular momentum
associated with the motion of a particle about an origin, equal to the cross product
of the position vector (r) with the linear momentum (p = mv):
L = r x p. Although r and p are constantly changing
direction, L is a constant in the absence of any external force on the system.
Also known as orbital momentum.
Fr.: axe orbital
The → perpendicular to the → orbital plane.
Fr.: débris spatial
Objects in orbit around Earth created by humans, that no longer serve any useful purpose. They consist of everything from entire spent rocket stages and defunct satellites to explosion fragments, paint flakes, dust, and slag from solid rocket motors, and other small particles. Also called space junk and space waste.
elektron-e madâri (#)
Fr.: électron orbital
An electron contained within an atom which may be thought of as orbiting around the nucleus, in a manner analogous to the orbit of a planet around the Sun.
Fr.: élément orbital
Any of the six parameters needed to specify the → orbit of an object around a → primary body (such as a planet around the Sun or a satellite around the Earth) and give its position at any instant. Two of them define the size and the form of the orbit: → semi-major axis (a) and → eccentricity (e). Three angular values determine the orbit position in space: the → inclination (i) of the object's → orbital plane to the reference plane (such as the → ecliptic), the → longitude of ascending node (Ω), and the → argument of periapsis (ω). And finally the sixth element is the → time of periapsis passage which allows calculating the body's position along the orbit at any instant.
Fr.: énergie orbitale
The → sum of the → potential energy and the → kinetic energy of an object in → orbit.
Fr.: inclinaison orbitale
An → orbital element that defines the angle between the orbital plane of a solar system body (planet, comet, asteroid) and the plane of the ecliptic. The orbital inclination of the Earth's orbit is 0°; those of Mercury, Venus, and Mars are 7.01°, 3.39°, and 1.85° respectively.
→ orbital; → inclination .
Fr.: mainoeuvre orbitale
The moving of a spacecraft between two different orbits resulting from a change in its velocity (acceleration). Generally, manoeuvres are caused by → thrust from the spacecraft's motors.
Fr.: mainoeuvre orbitale
Fr.: migration orbitale
Theoretical prediction according to which a → giant planet, formed in the outer regions of a → protoplanetary disk, could migrate inward by losing → energy and → angular momentum as the result of → gravitational interactions with the remnants of the disk. This orbital migration could explain the presence of giant gaseous Jupiter-like planets (→ hot Jupiters) very close to their host stars.
Fr.: nœud orbital
One of the two points of intersection of the orbit of a secondary body with the plane of reference through the primary.
Fr.: paramètre orbital
dowre-ye medâri (#)
Fr.: période orbitale
The time interval between two successive passages of an object through the same point in its orbit around another object.
Fr.: phase orbitale
In → photometry of → binary stars or → two-body systems, the number of whole or fractional orbits completed, from the point the photometry begins. The point is conventionally chosen as the position at which the → primary star eclipses the → secondary star, and therefore the → light curve is at a minimum. The phase keeps counting indefinitely, thus the secondary star gets eclipsed at phase 0, 1, 2, 3, and so on. At these phases the primary lies between the secondary and the observer. An orbital phase of 0.5 corresponds to halfway through the binary orbit, 0.75 is three-quarters the way through, and so on.