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

The → peak luminosity of a → Type Ia supernova is proportional to the rate of → radioactive decay and hence directly proportional to the mass of ⁵⁶Ni.

Arnett, W. D. 1982, ApJ, 253, 785; → rule.

Chemistry: Of, relating to, or containing the six-carbon ring typical of the benzene (C₆H₆) series and related organic groups.

M.E. aromatyk, from M.Fr. aromatique, from L. aromaticus, from Gk. aromatikos, from aroma "seasoning, sweet spice," of unknown origin.

An organic compound which contains benzene rings in its structure. The simplest is therefore benzene (C₆H₆). Aromatic compounds have a planar ring of atoms linked by alternate single and double bounds.

→ aromatic; → compound.

A family of strong infrared emission bands at 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 μm which are widely observed in a large variety of objects, such as → H II regions, → reflection nebulae, → planetary nebulae, and the → diffuse interstellar medium of our galaxy and other galaxies. Solar system objects, such as carbonaceous → meteorites and → interplanetary dust particles are also known to display these features. They are suggested to be due to → polycyclic aromatic hydrocarbons.

→ aromatic; → infrared; → band.

1) To set in a rank or row. To put in order.
2) Music: To adapt for other instruments or voices.

From M.E. arayngen, from M.Fr. arangier, from O.Fr. arengier, from a- "to," → ad-, + rangier "set in a row," from rang, → rank.

Rezgidan "to set in a row," from Lori rezg "row," related to râst, → right, Av. rāz- "to direct, draw a line;" probably ultimately from Proto-Ir. *Hrazaka- "row."

The act of arranging or being arranged. Result or manner of arranging.

Verbal noun of → arrange.

1) A system of telescopes coupled together, using → interferometric techniques, to increase the angular resolution or the sensitivity.
2) A two-dimensional detector comprising a large number of identical, individual detectors that can be used simultaneously, e.g. a → CCD.
3) A series of numbers or symbols arranged in some geometric pattern, as in a matrix.

Array, from M.E. arraien, from Anglo-Norman arraier, from V.L. *arredare.

Ârast "set in order," from ârastan, ârâstan "to set in order," Mid.Pers. ârây-, ârâstan, from â- + Av. râd- "to make ready, prepare;" PIE *ar- "to fit together."

An important relationship in physical chemistry that combines the concepts of → activation energy and the → Maxwell-Boltzmann distribution law. It is expressed by: k = Ae^-E_a/(RT), where k is the chemical → reaction rate, E_a is the activation energy, R is the → gas constant, and T is → temperature.

Named for Svante Arrhenius (1859-1927), Swedish chemist and physicist who suggested the relationship in 1889.

The precise time at which the gamma burst photons hit a detector. Measuring the time difference between the arrival time of the photons at different telescopes separated by known distances permits to determine the burst direction.

Arrival, n. from arrive + → -al. Arrive, from O.Fr. ariver "to come to land," from V.L. *arripare "to touch the shore," from L. ad ripam "to the shore," from → ad "to" + ripa "shore;" → time.

Zamân, → time; raseš n. from rasidan "to arrive," Mid.Pers. rasitan, O.Pers./Av. rasa- present stem of ar- "to move, go or come toward," cf. Skt. ar-, rcchati.

A slender, straight, generally pointed missile or weapon made to be shot from a bow and equipped with feathers at the end of the shaft near the → nock, for controlling flight (Dictionary.com). → Sagitta.

M.E. arewe, arwe, O.E. earh, possibly borrowed from O.N. ör; ultimately from PIE *arku- "bow and/or arrow," → arc.

Peykân "arrow, javelin" (cognate with afkan-, afkandan "to throw, cast away," parâkan-, parâkandan "to scatter, to disperse"), ultimately from Proto-Iranian *paiti-kan- "to throw against," from *paiti- "against, opposite, back" (cf. Mod.Pers. pâd- "against, contrary to;" Mid.Pers. pât-; O.Pers. paity "against, back, opposite to, toward, face to face, in front of;" Av. paiti; Skt. práti "toward, against, again, back, in return, opposite;" Pali pati-; Gk. proti, pros "face to face with, toward, in addition to, near;" PIE *proti) + *kan- "to throw."

A silver-gray black metallic → chemical element which is very brittle; symbol As. → Atomic number 33; → atomic weight 74.9216; → boiling point 613.0 °C (sublimation); → valence -3, 0, +3, or +5. The uncombined element is not considered poisonous, but many of its compounds are extremely so, and are used in medicine and for destroying pests. Its longest-lived radioactive → isotope, ⁷³As, has a → half-life of 80.3 days.

M.E. arsenik, from O.Fr. arsenic, from L. arsenicum, from Gk. arsenikon "arsenic," adapted from Syriac (al) zarniqa "arsenic," from Mid.Pers. zarnik "arsenic," literally "gold-colored," probably because of the lemon-yellow color of arsenic trisulphide (Mod.Pers. zarnix, zarni "arsenic"), from zarr, zar "gold" (+ -ik→ -ic); Av. zaranya-, zarənu- "gold;" O.Pers. daraniya- "gold;" cf. Skt. hiranya- "gold;" also Av. zaray-, zairi- "yellow, green;" Mod.Pers. zard "yellow;" Skt. hari- "yellow, green;" Gk. khloe literally "young green shoot;" L. helvus "yellowish, bay;" Rus. zeltyj "yellow;" P.Gmc. *gelwaz; Du. geel; Ger. gelb; E. yellow.

Ârsenik, loan from Fr., as above.

The process or product of human activity which is the expression of creativity and/or imagination that appeals to the senses or emotions.

From O.Fr. art, from L. artem, (nominative ars) "art, skill, craft;" from PIE base *ar- "to fit, join;" cf. Mod.Pers. arm "arm, from the elbow to the shoulder;" Av. arma-, arəmo- "arm;" Skt. irma- "arm;" Gk. arthron "a joint;" L. armus "shoulder."

Honar, from Mid.Pers. hunar "skill, ability, virtue, manliness;" O.Pers. hūnarā- "abilities, skills;" Av. hunara- "ability, skill"; cf. Skt. sūnára- "powerful, joyous, beautiful;" Proto-Iranian *Hnar- "to be able, strong."

A blood vessel that conveys blood from the heart to any part of the body (Dictionary.com).

M.E. arterie, O.Fr. artaire, from L. arteria, from Gk. arteria "windpipe," also "an artery," as distinct from a vein; related to aeirein "to raise."

Sorxrag, literally "red vessel," from sorx, → red, + rag, → vessel.

1) A nonfictional prose composition usually forming an independent part of a publication in a magazine.
2) A written document devoted to a scientific research and appearing in specialized journal.

Article, from O.Fr. article, from L. articulus, diminutive of artus "a joint".

Vetâr, from Kurd. witâr "article, speech," from witten "to speak, say," from wit-; cf. Pers. vât "letter, word," vâžé "word;" Av. vac- "to speak, say;" Proto-Iranian *uac- "to say, speak;" → letter.

1) An object made by a human being, typically one of cultural or historical interest.
2) Something observed in a scientific investigation or experiment that is not naturally present but occurs as a result of the preparative or investigative procedure (OxfordDictionary.com).

From It. artefatto, from L. arte "by skill" (ablative of ars "→ art") + factum "thing made," from facere "to make, do," → -fy.

Dasâc "hand made," from das variant of dast, → hand, + sâc, variant of sâz-, sâxtan, → agree.

Not occurring naturally; produced by man.

M.E., from O.Fr., from L. artificialis "belonging to art," from artificium "craftsmanship."

Sâxtegi "artificial," from sâxtan "to build, to make," → structure.

A shallow flat vessel filled with → mercury or some other viscous → liquid used in special → sextant for measuring altitudes of celestial bodies at sea in the absence of a → visible horizon.

→ artificial; → horizon.

An artificially created language system for international communication or for a specific intellectual or scientific purpose. Examples include Esperanto, computer programing languages, → symbolic logic, and → tensor analysis.

→ artificial; → language.

Any light other than that which proceeds from the heavenly bodies.

→ artificial; → light.

A man-made equipment that orbits around Earth or a solar system body.

→ artificial; → satellite.