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

A combining form meaning "something drawn, written" (diagram, spectrogram, oscillogram).

From Gk. -gramma, combining form of gramma "something written or drawn," → graph.

-Negâšt, from negâšt "drawn, written;" p.p. of negâštan, negârdan "to paint, write," → graph.

A geometrical representation of → complex numbers, which like the → Cartesian coordinates, uses two reference perpendicular axes. The horizontal axis represents the → real number part of the number and the perpendicular axis the → imaginary number part.

Named after Jean Robert Argand (1768-1822), a Swiss mathematician, who introduced this representation; → diagram.

An auxiliary observing program to be carried out at telescope in case the atmospheric conditions make the main program unfeasible.

Backup, from → back + up; → program.

Barnâmé, → program; yadaki "reserve, substitute," from yadak "a led horse."

A set of nebular → emission line diagrams used to distinguish the ionization mechanism of → nebular gas. The most famous version consists of [N II]λ6584/Hα versus [OIII] λ5007/Hβ. The next two more commonly used BPT diagnostics are [S II] λλ6717,6731/Hα versus [O III] λ5007/Hβ and [O I] λ6300/Hα versus [O III]λ5007/Hβ. These diagrams use strong, optical lines of close proximity in the ratios to limit → reddening and → spectrophotometric effects. They are able to clearly distinguish different classes of → ionization, for example → LINERs from normal → H II regions and → active galactic nuclei.

Baldwin, J. A., Phillips, M. M., Terlevich, R., 1981 PASP 93, 5; → diagram.

A graph on which the latitudes of → sunspots are plotted against time. It shows how sunspots migrate from high latitudes (30°- 40° north or south) to the solar equator (latitude of about 5°) during each → solar cycle, according to → Sporer's law. The shape of these distributions, when represented for both hemispheres, resembles the wings of a butterfly. The diagram was first created by Edward W. Maunder in 1904 to illustrate the solar cycle (M.S.: SDE).

Butterfly, from M.E. butterflye, from O.E. butorfleoge, from butor, butere "butter" floge "fly," but the etymology is not clear; → diagram.

Nemudâr, → diagram; parvânevâr "resembling a butterfly," from parvâné "butterfly" + -vâr similarity suffix.

A diagram based on two photometric colors usually representing the same class of astronomical objects.

→ color; → diagram.

A form of → Hertzsprung-Russell diagram in which the luminosity is the vertical axis and the → color index the horizontal axis.

→ color; → luminosity, → diagram.

A form of → Hertzsprung-Russell diagram in which the visual absolute magnitude M_v is the vertical axis and the → color index the horizontal axis.

→ color; → magnitude, → diagram.

Same as → concept map.

→ conceptual; → diagram.

A plot showing a summary of correlation at different periods of time.

Correlo-, from → correlation; → -gram.

A graphic representation of the behavior of one or several variables.

From Fr. diagramme, from L. diagramma, from Gk. diagramma "that which is marked out by lines," from diagraphein "to mark out by lines," from dia- "across, out" + graphein "to write, draw," → -graphy.

Nemudâr agent noun of nemudan "to show," → display, from the past stem nemud + -âr, such as xâstâr, foruxtâr, padidâr, parastâr (contraction of *parastidâr).

A program that can run on a → computer. It uses an → executable file.

→ executable; → program.

A schematic representation, in quantum electrodynamics and quantum chromodynamics, of the way elementary particles like electrons and protons interact with each other by exchanging photons. Use of Feynman diagrams can greatly reduce the amount of computation involved in calculating a rate or cross section of a physical process.

After the American physicist Richard P. Feynman (1918-1988), Nobel prize 1965; → diagram.

A unit of mass equal to one thousandth of a kilogram.

From Fr. gramme, from L.L. gramma "small weight," from Gk. gramma "small weight," originally "letter of the alphabet," from stem of graphein "to draw, write."

Geram, loanword from Fr. gramme, as above.

1) The study of the way the sentences of a language are constructed; → morphology and → syntax.
2) These features or constructions themselves (Dictionary.com).

M.E. gramarye, from O.Fr. gramaire "grammar; learning," especially Latin and philology, an "irregular semi-popular adoption" of L. grammatica, from Gk. grammatike (tekhne) "(art) of letters" with a sense of both philology and literature, from grammatikos "pertaining to or versed in letters or learning," from gramma "letter," → -gram.

Dastur-e zabân, literally "language rule," from dastur "rule; mandate, command; religious authority (of the Zoroastrians);" Mid.Pers. dast "able, capable;" Av. danh- "to teach, instruct;" cf. Skt. dams- "to show or teach wonderful skills, perform wise;" Gk. didasko "I learn;" PIE *dens- "to become skilfull; to teach, instruct" (Cheung 2007); + zabân, → language.

A specialist or expert in grammar.

From O.Fr. gramairien "learned man, person who knows Latin," agent noun from grammaire, → grammar.

Zabân-dasturdân, literally "knower of grammar," from zabân-dastur→ grammar + dân agent noun and present stem of dânestan, → know.

Of or relating to → grammar; conforming to standard usage.

From M.Fr. grammatical and directly from L. grammaticalis "of a scholar," from grammaticus "pertaining to → grammar."

Dastur-e zabâni, zabân-dasturidastur-e zabân, zabân-dastur, → grammar.

An inflectional category, basically pertaing to nouns and pronoun, which marks their relationship with other parts of the sentence. sentence. → accusative case, → nominative case, → genitive case, → dative case, → ablative case, → vocative case, → imperative case.

→ grammatical; → case.

Same as → Hertzsprung-Russell diagram.

Short for → Hertzsprung-Russell diagram.

A record made by a → heliograph.

→ helio-; + → -gram.