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

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 brightest star in the constellation → Canis Minor. With an → apparent visual magnitude of 0.34, Procyon is the eighth brightest star in the night sky. It is actually a → binary star system, consisting of a white → main sequence star of → spectral type F5 IV-V, named Procyon A, and a faint → DA white dwarf companion, named Procyon B. The distance of the system is 11.46 → light-years and the revolution period about 40 years. Procyon A is of → solar metallicity. It has an → effective temperature of about 6600 K and a mass of 1.43 M_sun. The age of the white dwarf is estimated to be 1.7 Giga years. Also called Procyon A, HR 2943, HD 61421 (see Chiavassa et al. 2012, arXiv:1201.3264 and references therein).

Procyon, literally "before the dog," referring to the mythical dog, → Canis Minor, from L. from Gk. prokyon, from → pro- "before" + kyon, kuon "dog;" cognate with Pers. sag, as below.

Farâsag, from farâ- "before," → pro-, + sag "dog;" Mid.Pers. sak/sag Av. spā-; cf. Skt. svā-; Gk. kuon; L. canis (Fr. chien); Arm. šun; O.E. hund; O.H.G. hunt; O.Ir. cu; Welsh ci; Rus. sobaka; PIE *kwon-. In several Pers. dialects this term has conserved its older Av. form with respect to its Modern "official" counterpart: Tâleši, Tâti: espa; štiyâni: esb; Kâšâni, Sorxeyi: esbâ; Lâsgardi: aesbae.

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.

Neutrons emitted immediately by a nucleus undergoing fission, as opposed to → delayed neutrons, which are emitted by one of the fission products an appreciable time interval after the fission event (from a few milliseconds to a few minutes).

→ prompt; → neutron.

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.

A grammatical element which replaces a noun previously mentioned.

From M.Fr. pronom, from L. pronomen, from → pro- "in place of" + nomen, → name.

Farânâm, literally "noun (put) forth (to replace)," from farâ- "forward, along, opposing, facing," → pro- + nâm, → name.

1) To enunciate or articulate (sounds, words, sentences, etc.).
2) To utter or sound in a particular manner in speaking:

→ pro-; → announce.

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.