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

A mathematical function whose integral over any interval gives the probability that a continuous → random variable has values in this interval. Also known as → density function, frequency function, → probability function.

→ probability; → density; → function.

The function that describes the range of possible values that a random variable can attain and the probability that the value of the random variable is within any (measurable) subset of that range.

→ probability; → distribution.

A function that represents a probability distribution in terms of integrals. Also called probability density function or density function.

→ probability; → function.

The act of moving along or proceeding in orderly succession or in a formal and ceremonious manner, as a line of people, animals, vehicles, etc (Dictionary.com).

Verbal noun from → process.

The act of producing; creation; something that is produced; a product. → pair production

M.E., from O.Fr. production, from M.L. productionem, from L. productus, p.p. of producere "bring forth," from → pro- "forth" + ducere "to bring, lead."

Farâvareš "bringing forth," from far- "forth," → pro-, + âvareš, "bringing," verbal noun âvardan "to bring; to cause, produce" (Mid.Pers. âwurtan, âvaritan; Av. ābar- "to bring; to possess," from prefix ā- + Av./O.Pers. bar- "to bear, carry," bareθre "to bear (infinitive)," bareθri "a female that bears (children), a mother;" Mod.Pers. bordan "to carry;" Skt. bharati "he carries;" Gk. pherein; L. fero "to carry").

An occupation, especially one that requires prolonged training and a formal qualification.

From M.E., from O.Fr. profession, from L. professionem "public declaration," from professus "having declared publicly," ultimately from → pro- "forth" + fateri "to acknowledge, confess."

Pišé "profession, job," from Mid.Pers. pêšak "profession, job, work; class, group;" Av. pištra- "occupation; class, group," from paēs- "to paint; to adorn," paēsa- "adornment;" Mid.Pers. pēsīdan "to adorn;" O.Pers. pais- "to adorn, cut, engrave;" Mid.Pers. bišt-, bis- (nibištan, nibes- "to write"), Mod.Pers -vis, -veš (in nevis-, neveštan "to write"), pisé "variegated;" cf. Skt. piśáti "adorns; cuts;" Gk. poikilos "multicolored;" L. pingit "embroiders, paints;" O.C.S. pisati "to write;" O.H.G. fēh "multicolored;" Lith. piēšti "to draw, adorn;" PIE base *peik- "colored, speckled."

Relating to or belonging to a profession.

Pišekâr literally "doing as profession," from pišé, → profession, + kâr "work," from kar-, kardan "to do, to make," → -or.

→ profession; → -al.

A person who practices astronomy as a profession rather than as a hobby, in contrast to an → amateur astronomer.

→ professional; → astronomer.

A rotational or orbital movement that is the same as most bodies within a celestial system. In the solar system, the apparent eastward motion of a celestial body on the celestial sphere. Opposed to → retrograde motion. Same as → direct motion.

From → pro- "forward" + grade, from L. gradi "to go, step, walk;" → motion.

Jonbeš, → motion; farârow, from farâ- "forward," → pro-, + row present stem of raftan "to go, walk;" Mid.Pers. raftan, raw-, Proto-Iranian *rab/f- "to go; to attack."

Math.: A succession of numbers or quantities in which there is a constant relation between each member and the one succeeding it. See also → arithmetic progression, → geometric progression, → harmonic progression.

From O.Fr. progression, from L. progressionem "a going forward," from progressus, p.p. of progredi "go forward," from → pro- "forward" + gradi "to step, walk," from gradus "step."

Farâyâzi, from farâ-, → pro-, + yâzi, verbal noun of yâzidan "to stretch out the arms; grow up;" Parthian Mid.Pers. y'd "to reach a goal, come to, stretch out;" Av. yat- to reach, take one's place," yaiiata "places,' frā-iiatāt "has reached;" cf. Skt. yat- "to be in place, put in place, line up;" PIE base *iet- "to be in place."

The → angular velocity of a star deduced from the → rotational broadening of its → spectral lines. It is expressed as v sini, where i is the → inclination of the rotational axis with respect to the normal to the → plane of the sky. The real equatorial rotational velocity can be determined only if the inclination of the rotational axis is known.

Projected, p.p. of → project; → rotational; → velocity.

1) The act, process, or result of projecting.
2) The act of reproducing on a surface, by optical means, a remote image on a film, slide, etc.

Verbal noun of → project.

1) The act of promoting someone to a higher job, grade, or rank, or the fact of being so promoted.
2) Support or encouragement of the progress, growth, or acceptance of something.
3) An act, event, or offer that helps to increase interest in or demand for something (FreeDictionary.com).

Verbal noun of → promote.

Farkašan, literally "draw forward, pull up," from far-, variant of farâ-, → pro-, + kašan "drawing, pull," from kaš present stem of kašidan, → galaxy, + noun suffix -an.

A mechanism predicted by theoretical models of → supernova explosion in the case when the → supernova shock breaks through the outer edge of the collapsing → iron core before losing all of its energy (through → photodisintegration of the iron nuclei) and manages to expel the stellar envelope. Compare with → delayed supernova explosion.

→ prompt; → supernova; → explosion. See also → delay.

1) The act or result of producing the sounds of speech, including articulation, stress, and intonation, often with reference to some standard of correctness or acceptability.
2) An accepted standard of the sound and stress patterns of a syllable, word, phrase, etc.(Dictionary.com).

Verbal noun of → pronounce.

Physics: The act or process of propagating, especially the process by which a disturbance, such as the motion of electromagnetic or sound waves, is transmitted through a medium such as air or water. Linguistically related notions: → diffusion (پخش); → dispersion(پاشش); → scattering (پراکنش); → diffraction (پراش).

Verbal noun of → propagate.

A parameter, denoted k = 2π/λ, that along with the → angular frequency, ω = 2πν, is used to express the equation of → simple harmonic motion, y = cos (ωt - kx + π/2). Same as → wave number.

→ propagation; → number.

The apparent motion of a star across the sky (not including a star's parallax), arising from the star's velocity through space with respect to the Sun. Proper motion is usually tabulated in star catalogs as changes in right ascension and declination per year or century. See also: → proper motion distance.

→ proper; → motion.

The distance derived from the → proper motion of an object. If an object has a known → transverse velocity  u, and has an observed angular motion of dθ/dt, then the proper motion distance is defined as: d = u/(dθ/dt).

→ proper; → motion; → distance

Comparative relation between things, sizes, quantities, numbers, parts, etc.
Math.: A statement of the equality of two ratios.

M.E. proporcio(u)n, from O.Fr. proportion, from L. proportio "comparative relation, analogy," from the phrase pro portione "according to the relation" (of parts to each other), from pro "for" + portio "part, shar."

Barpâreš, from bar- "on; up; upon; in; into; at; forth; with; near; before; according to" (Mid.Pers. abar; O.Pers. upariy "above; over, upon, according to;" Av. upairi "above, over," upairi.zəma- "located above the earth;" cf. Gk. hyper- "over, above;" L. super-; O.H.G. ubir "over;" PIE base *uper "over") + pâr "part, portion, piece" (variants pâréparré "portion, segment (of an orange)," pargâlé, "piece, portion; patch;" (dialects Kermâni pariké "portion, half;" Tabari perik "minute quantity, particle;" Lârestâni pakva "patch;" Borujerdi parru "patch"); Mid.Pers. pârag "piece, part, portion; gift, offering, bribe;" Av. pāra- "debt," from par- "to remunerate, equalize; to condemn;" PIE *per- "to sell, hand over, distribute; to assigne;" Gk. peprotai "it has been granted;" L. pars, as above; Skt. purti- "reward;" Hitt. pars-, parsiya- "to break, crumble") + -eš suffix.