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

A diagram involving → formal compactification of → space-time used in → general relativity to describe the causal properties of the space-time. Only two of the space dimensions are shown and horizontal lines represent space, while vertical lines belong to time. The → null geodesicss are at 45°, which facilitates the visualization of → light cones. The major feature of Penrose-Carter diagram is representing the whole space-time on a finite surface, while putting → spacelike and → timelike infinities at finite distance.

Named for Roger Penrose (1931-) and Brandon Carter (1942-) who introduced it independently; → diagram.

A plot for examining frequency-domain data in an equi-spaced → time series. The periodogram is the → Fourier transform of the → autocovariance function. The periodogram method relies on the definition of the → power spectral density .

→ period; + euphonic infix -o-; → -gram.

A graph showing the equilibrium relationships between phases (such as vapor-liquid, liquid-solid) of a chemical compound, mixture of compounds, or solution.

→ phase; → diagram.

A plan or schedule of activities, procedures, etc., to be followed.
Computers: A precise sequence of instructions in a programming language that tells a computer to perform a task.

From L.L. programma "proclamation, edict," from Gk. programma "a written public notice," from the stem of prographein "to write publicly," from → pro- "forth" + graphein "to write."

Barnâmé, originally "model, examplar; acount-book," 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") + nâmé "letter; book" (Mid.Pers. nâmak "inscription; letter; book," related to nâm "name;" Mid.Pers. nâm; O.Pers./Av. nâman-; cf. Skt. nama-; Gk. onoma, onuma; L. nomen; PIE *nomen-).

Stars for the observation of which telescope time has been awarded.

→ program; → star.

A computer expert who carries out → programming.

Agent noun of the verb → program.

The process of writing, testing, debugging/troubleshooting, and maintaining the source code of computer programs.

Verbal noun of → program.

Barnâme-sâzi, from barnâmé, → program, + sâzi verbal noun of sâxtan, sâzidan "to build, make, fashion; to adapt, adjust, be fit" (from Mid.Pers. sâxtan, sâz-, Manichean Parthian s'c'dn "to prepare, to form;" Av. sak- "to understand, to mark," sācaya- (causative) "to teach").

Graphic display of measurements by a → radar of mineral deposits on a planetary surface.

→ radar; → chart.

A simple way of representing the → space-time continuum, usually including time and only one spatial dimension. The curve of a particle's equation of motion on a space-time diagram is called a → world line. Same as → Minkowski diagram.

→ space; → time; → diagram.

A plot of the intensity of light at different wavelengths obtained using a spectrograph.

→ spectro-; → -gram.

An image of the Sun taken in the light of one particular wavelength.

→ spectro-; → heliogram.

A spacial → Hertzsprung-Russell diagram (HRD) which is independent of distance and extinction measurements. The sHRD is derived from the classical HRD by replacing the luminosity (L) to the quantity ℒ = T ⁴_eff/g which is the inverse of the flux-weighted gravity introduced by Kudritzki et al. (2003). The value of ℒ can be calculated from stellar atmosphere analyses without prior knowledge of the distance or the extinction. In contrast to the classical T_eff-log g diagram (→ Kiel diagram), the sHRD sorts stars according to their proximity to the → Eddington limit, because ℒ is proportional to the Eddington factor Γ = L/L_Edd according to the relation ℒ = (1/4πσG)(L/M) = (c/(σκ)Γ, where σ is the → Stefan-Boltzmann constant, κ is the electron → scattering  → opacity in the stellar envelope, and the other symbols have their usual meanings (Langer, N., Kudritzki, R. P., 2014, A&A 564, A52, arXive:1403.2212, Castro et al., 2014, A&A 570, L13.

→ spectroscopic; → H-R diagram.

A graph on which two color indices such as B-V and U-B are plotted, one along each axis, for a sample of stars or other objects, such as stars.

→ two; → color; → diagram.

A schematic diagram using circles to represent sets and the relationships between them. Each circle represents one set. Two or more may be overlapped. The areas of overlap indicate subsets.

Named after John Venn (1834-1923), a British logician and philosopher, who introduced the diagram; → diagram.