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

The forces of jets from a comet's nucleus that can cause a rocket-like effect and alter a comet's direction of motion slightly.

→ non-; → gravitational; → force.

Having an unknown or unacknowledged name. → anonymous object.

L. annymus, from Gk. annumos "nameless," from → an- "without" + onoma, onuma "name". Compare with L. nomen, Skt. nama, Av. nama, Mod. Pers. nâm, PIE *nomen "name".

Anâm, from Persian → a-, an- "without" + nâm "name," as above. Binâm, from bi- "without" + nâm.

An → astronomical object which has not been catalogued.

→ anonymous; → object.

The episodic occurrence of abrupt → mass loss in → Be stars resulting in → Balmer lines in emission and → infrared excess. The Be phenomenon results from a combination of a long-term secular effect and short-term instabilities, such as pulsation. The secular evolution brings the star close enough to the critical → break-up velocity, so that the additional velocity field due to the instability may allow some mass ejection (Maeder 2011).

→ Be star; → phenomenon.

Canon of Eclipses. The most famous catalogue of solar and lunar eclipses. Published in 1887 by Theodor von Oppolzer, the catalogue contains the elements of all solar and lunar eclipses between 1208 BC and 2161 AD. It has been superseded by the calculations of F. Espenak and J. Meeus, Five Millennium Canon of Solar Eclipses: -1999 to +3000 (NASA/TP-2006-214141) and Five Millennium Canon of Lunar Eclipses: -1999 to +3000 (NASA/TP-2009-214172).

Canon, from L. canon, from Gk. kanon "a straight rod, a measuring rod, rule;" Ger. Finsternisse, plural from finsternis "eclipse; darkness," from finster "dark," M.H.G. vinster, O.H.G. finstar "dark" + -nis suffix forming abstract nouns, → -ness.

Fehrest "index, catalogue, canon," → index; gerefthâ plural of gereft, → eclipse.

1) General: Pertaining to, established by, or conforming to a canon, i.e. a law or a general rule (especially in ecclesiastical matters).
2) Math.: Relating to the simplest or standard form of a general function, equation, rule, etc.

M.M. canonicalis, from canonic(us), from L. canon, from Gk. kanon "a straight rod, a measuring rod, rule " + alis, → -al.

Hanjârvâr, from hanjâr "a mason's rule, any string or instrument used by builders in laying stones straight; rule, law, way, custom; a norm" + -vâr suffix meaning "having, endowed with; like, in the manner of."

A periodic change in one of the components of the orbit of a celestial object.

→ canonical; → change.

Any set of generalized coordinates of a system together with their → conjugate momenta.

→ canonical; → coordinates.

The highest correlation between linear functions of two data sets when specific restrictions are imposed upon them.

→ canonical; → correlation.

The most general form of an equation.

→ canonical; → equation.

The simplest expression of an equation, statement, or rule.

→ canonical; → form.

A two-component stellar → initial mass function with → slopes of 1.3 and 2.3 for massive and low mass stars, respectively. Also called universal IMF.

→ canonical; → IMF.

A model for the formation of the Moon according to which the → Moon results from a giant impact. A Mars-sized body (often referred to as → Theia) obliquely collided with the proto-Earth at the mutual escapee velocity. This specific giant impact is often used to represent all giant impacts. A recent advanced version of the canonical model is called → giant impact hypothesis.

→ canonical; → model.

Same as → conjugate momentum.

→ canonical; → momentum.

A physical upper mass limit near 150 Msun assumed for the stellar → initial mass function (Kroupa et al. 2012, arXiv:1112.3340).

→ canonical; → upper; → limit.

A generalized coordinate and its → conjugate momentum.

Canonically, adverb from → canonical; → conjugate; → variable.

The probability distribution of the various possible states of a certain → quasi-closed subsystem.

→ Gibbs free energy; → canonical; → distribution.

Same as → principle of non-contradiction.

→ law; → non-; → contradiction.

A prefix meaning "not."

From O.Fr. non-, from L. non "not," from Old L. noenum "not one;" in some cases perhaps from M.E. non "not" (adj.), from O.E. nan.

Nâ- "no, not," variants na, ni, ma- (prohibitive) "not;" from Mid.Pers. nê, ma "no, not;" O.Pers. naiy, nai "not;" Av. nôit, naē "not;" cf. Skt. ná "not;" cf. L. ne-, in-, un-; Gk. ni; Lith. nè; O.C.S. ne "not;" PIE *ne-.

A → transcendental function. Examples are: exponential, logarithmic, and trigonometric functions.

→ non-; → algebraic + → function.