An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

Easily seen or noticed; readily → visible or → observable (Dictionary.com).

From L. conspicuus "visible, open to view," from conspicere "to look at, observe, see, notice," from → com-, intensive prefix, + specere "to watch, look at," → spectrum.

Hoveydâ "conspicuous, manifest, evident," variant vidâ, probably related to Av. hu-vaēiδiia- "good knowledge, well-known," from hu- "good, well," → eu-, + vaēiδiia- "knowlege, known."

A quantity that does not change during a particular process.

L. constantem "standing firm, stable," pr.p. of constare, from → com- "together" + stare "to stand;" PIE base *sta- "to stand;" cf. O.Pers./Av. sta- "to stand, stand still; set," Pers. istâdan "to stand," Skt. sthâ- "to stand," Gk. histemi "put, place, weigh," stasis "a standing still,"

pâyâ verbal adj./noun from pâyidan "to stand firm, to be constant, steady, fixed," Mid.Pers. pâyitan, pâtan, pây- "to protect; wait, stand," Sogdian p'y "to protect, watch over," O.Pers./Av. pâ(y)- "to protect, keep" pâtar- "protector, watcher," cf. Skt. pâ- "to protect, keep," pâti "protects," Gk. poimen "shepherd," poma "lid, cover," L. pastor "shepherd," panis "bread;" PIE base *pa- "to protect, guard, pasture, feed."

The maximum amount of the apparent yearly displacement of a star, resulting from the → aberration of starlight. The value of the constant of aberration, κ, at J2000.0 is 20".49552. κ = (v/c) csc 1", where v is the average speed of the Earth about the Sun and c is the → speed of light in vacuum. The Earth's speed is given by: v = 2πa / [P(1 - e²)^1/2], where a is the → semi-major axis of the Earth's orbit, e is the → eccentricity of the Earth's orbit, and P is the → sidereal period of the Earth. Same as → constant of annual aberration. See also → constant of diurnal aberration.

→ constant; → aberration.

Same as → constant of aberration.

→ constant; → annual; → aberration.

The quantity 0''.3200 ρ cos φ', where ρ is the geocentric distance of the observer measured in units of → equatorial radius the Earth and φ' is the observer's → geocentric latitude. The numerical part is equal to 2πa csc1'' / (cP), where a is the equatorial radius of the Earth, P is its → sidereal period of rotation, and c is the → speed of light in vacuum.

→ constant; → diurnal; → aberration.

→ gravitational constant.

1) Classical mechanics: A variable X whose total rate of change dX/dt along the path of a → dynamical system is zero. In other words, a function of an object's position, velocity, or both that does not change even as the object moves. For example, the total energy of a → simple harmonic oscillator is a constant of the motion.
2) Quantum mechanics: An → observable that remains constant in time. As an example, the energy is a constant of the motion of all systems whose → Hamiltonian does not depend explicitly upon time.

→ constant; → motion.

A grouping of conspicuous stars that, when seen from Earth, form an apparent pattern. The sky is divided into 88 constellations. → asterism.

From O.Fr. constellation, from L.L. constellationem (nom. constellatus) "set with stars," from L. → com- "with" + p.p. of stellare "to shine," from stella, → star.

Hamaxtarân, from ham- "with, together" + axtar→ star + -ân suffix denoting group.

1) Forming part of a whole; component.
2) Politics, law: Having the power to frame a constitution or to constitute a government; a person who appoints another to act for him, as by power of attorney.
3) Linguistics: A word, phrase, or clause forming a part of a larger construction (TheFreeDictionary.com).

→ constitute; → -ent.

1) To make up; form; compose.
2) To appoint to an office or function.
3) To set up (a school or other institution) formally; found.
4) Law: To give legal form to (a court, assembly, etc.) (TheFreeDictionary.com).

From L. constitutus, p.p. of constituere "to cause to stand, set up, fix, place, establish, set in order; form something new," from → com- an intensive prefix + statuere "to set," from PIE root *sta- "to stand, make or be firm." cf. Pers. istâdan "to stand," → opposition.

Âsâtidan, from intensive prefix â- + sât variant of sâz-/sâxtan "to build, make, prepare," cf. Gazi sât- "to be reconciled with," Abyaneyi, Abuzeydâbâdi, Nâyini, Târi. sâta-/sâj-, Anâraki, Varzeneyi sâte-/sâj-, Ardestâni sûtte/sûj-, Hamadâni satän/saj-, Esfahâni satän/saz-, Jowšaqâni bam-sa:t- "to do, build," Xonsâri sât-/sâz-, Mahalâti sât/sâj- "to prepare, do;" Mid.Pers. sac, saz- "to be fitting, becoming, necessary," sac-, sâz- "to make, prepare;" Mod.Pers. sâz-, sâxtan "to build, construct, prepare;" cf. Skt. śak- "to be able, capable;" Proto-Ir. sac- "to fit, be suitable, be able, be in command of; to prepare" (Cheung, 2006).

1) The act or process of composing, setting up, or establishing.
2) The system of fundamental laws and principles that prescribes the nature, functions, and limits of a government or another institution (TheFreeDictionary.com).

Verbal noun of → constitution.

1) Of or relating to a constitution.
2) Consistent with, sanctioned by, or permissible according to a constitution (TheFreeDictionary.com).

→ constitution; → -al.

1) Making a thing what it is; essential.
2) Having power to institute, establish, or enact.

→ constitite; → -ive.

To confine forcibly, as by bonds; to force, compel, or oblige; to repress or restrain. → constrained body, → constrained system.

→ constraint.

A → rigid body whose displacement is prevented because it is under → constraint or a body that can move only in certain directions. Contrasted with → free body.

Constrained, p.p. of → constrain; → body.

Opposite of a → free system. See also → constraint.

Constrained, p.p. of → constrain; → system.

1) General: Limitation or restriction.
2) Mechanics: Any restriction imposed on the position or motion of a material system. Constraints are said to be internal if they do not impede free displacement of the system. All other kinds of constraints are called external. Systems subject only to internal constraints are free material systems.
3) Physics: A fact or condition, usually observational, that allows to reduce the number of free parameters in a theoretical model.

M.E. constreinte, from M.F., from constreindre, from L. constringere "to bind together, tie tightly," from → com- "together" + stringere "to bind, draw tight."

Pâvand "fetter, shackle," from pâ "foot" (Mid.Pers. pâd, pây; Khotanese fad; Av. pad-; cf. Skt. pat-, Gk. pos, genitive podos; L. pes, genitive pedis; P.Gmc. *fot, E. foot, Ger. Fuss, Fr. pied; PIE *pod-/*ped-) + vand, variant band "tie, band," (Mod.-Mid./Pers. bastan/vastan "to bind, shut," Av./O.Pers. band- "to bind, fetter," banda- "band, tie," Skt. bandh- "to bind, tie, fasten," PIE *bhendh- "to bind," cf. Ger. binden, E. bind).

Same as → Abbe number.

Noun from → constrain.

An → interference process in which the → amplitude of the resultant wave is greater than that of either individual waves. See also → destructive interference.

Constructive, from M.Fr. constructif or from M.L. constructivus, from L. construct-, p.p. stem of construere "to heap up," from → con- + struc- variant stem of struere "to build," → structure; → interference.

Andarzaneš, → interference; sâzandé "constructive," from sâxtan, → structure.

To seek advice or information from; ask guidance from.

From M.Fr. consulter, from L. consultere "to deliberate, consult," frequentative of consulere "to consult, deliberate, consider, ask advice," from → com- "together" + -sulere, from PIE *selh- "to take, grab," cognate with E. sell, sold.

Hagârdan, from ha-, variant of ham- "together," → com-, + gâr "to observe, consider," variants gar-, gâl- (as in engâridan "to suppose," negaristan "to observe, look, notice," segâlidan "to think, discuss, consider") ultimately from Proto-Ir. *kar- "to observe, consider," cf. Av. kar- "to remember, to impress on memory," Skt. kal- "to observe, conside," kalayati "considers, observes;" see also âgâridan, → consider.