plural of sidereal orbital period

(aerospace) An elliptical orbit used to transfer between two circular orbits of different radii in the same plane.

(space flight) A lunar-resonant orbit about the Earth with a period of 1/2 that of the Moon's (P/2 is an orbit that is approximately a fortnight long)

(algebra) A theorem which states that for each element of a given set that a given group acts on, there is a natural bijection between the orbit of that element and the cosets of the stabilizer subgroup with respect to that element.

(physics, chemistry) A method of determining the structure of a molecule by assuming that electrons are not fixed to bonds between individual atoms

(astronomy) The sidereal year of a planet. (I.e., in the definition for "sidereal year", replace "Earth" by the given planet.)

(science fiction) A satellite or space station, found in many different works of science fiction, meant to defend a planet against attack from space.

(of a black hole) Synonym of photon sphere

(ophthalmology, neurology) A collection of cranial nerve deficits associated with a mass lesion near the apex of the orbit, often leading to ophthalmoplegia.

(anatomy) One of two openings transmitting nerves and blood vessels to or from the orbit, situated superiorly between the greater wing and the lesser wing of the sphenoid bone.