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

A → NASA space telescope devoted to the hunt for planets orbiting the brightest stars in the sky, launched on April 18, 2018. The mission is planned to monitor at least 200,000 stars for signs of → exoplanets using the → planetary transit method. TESS is equipped with four identical refractive → cameras with a combined → field of view (FOV) of 24 × 96 degrees. Each camera consists of a → CCD detector assembly, a → lens assembly, and a lens hood. The → entrance pupil diameter is 10.5 cm and the wavelength range 600 to 1,000 nm. The satellite is a follow-up of NASA's → Kepler spacecraft, but focuses on stars that are 30 to 100 times brighter than those Kepler examined.

→ transit; → exoplanet; → survey.

A planet that passes in front of its star directly between Earth and the star. The → transit method is used for detecting → exoplanets around stars.

→ transit; → planet.

A Belgian facility devoted to the detection and characterization of → exoplanets and to the study of → comets (→ transiting planet) and other → small solar system bodies. It consists of two 60 cm robotic telescopes located at the → European Southern Observatory, → La Silla, in Chile and at Oukaïmden Observatory in Marroco.

→ transit; → planet; → planetesimal; → small; → telescope.

1) Passage from one position, state, stage, subject, concept, etc., to another.
2) A change between phases such as solid to liquid or liquid to gas.
3) A change in the → energy level or state of an atom or nucleus. → atomic transition, → bound-bound transition, → bound-free transition, → cascade transition, → discrete transition, → forbidden transition, → hyperfine transition, → nuclear transition, → permitted transition, → phase transition, → quark-hadron phase transition, → radiative transition, → rotational transition, → semi-forbidden transition, → transition disk, → transition function, → transition probability, → vibrational transition.

From L. transitionem (nominative transition) "a going across or over," noun of action from transire "go or cross over," from → trans- "across" + ire "to go."

Gozareš, verbal noun of gozaštan "to transit, pass," → transit, + -eš, → -tion.

The → accretion disk of a → T Tauri star that displays very weak or no → infrared excess at → near infrared wavelengths, but shows strong excess at → intermediate infrared and longer wavelengths. This happens when the hot inner dust disk has dissipated whereas the cooler outer disk is still intact.

→ transition; → disk.

The → probability of finding the → Universe in a → state labelled X₂ at a time t₂, if it was in a state X₁ at an earlier time t₁.

→ transition; → function.

The probability that a quantum-mechanical system will make a transition from a given initial state to a given final state.

→ transition; → probability.

In fluid mechanics, a flow composed of → laminar and → turbulent flows, for which the → Reynolds number is between 2300 and 4000.

→ transition; → flow.

1a) Mechanics: To subject a body to → translation.
1b) Math.: To perform a → translation.
2a) To turn from one language into another.
2b) To convert computer data to a different form according to an → algorithm.

M.E. translaten, from L. translatus, from → trans- "across" + latus suppletive p.p. of ferre "to carry;" cognate with Pers. bordan "to carry, transport;" Mid.Pers. burdan; O.Pers./Av. bar- "to bear, carry," barəθre "to bear (infinitive);" Skt. bharati "he carries;" Gk. pherein "to carry;" PIE base *bher- "to carry."

1) Tarâjâyidan, from tarâ-, → trans- "across" + jâ "place" (from Mid.Pers. giyag "place;" O.Pers. ā-vahana- "place, village;" Av. vah- "to dwell, stay," vanhaiti "he dwells, stays;" Skt. vásati "he dwells;" Gk. aesa (nukta) "to pass (the night);" Ossetic wat "room; bed; place;" Tokharian B wäs- "to stay, wait;" PIE base *ues- "to stay, live, spend the night") + -idan infinitive suffix.
2) Tarâzabânidan, from tarâ-, as above, + zabân "tongue; language" (Mid.Pers. uzwân "tongue; language;" O.Pers. hzanm, hizānam "tongue;" Av. hizuua-, hizū- "tongue;" cf. Skt. jivhā- "tongue;" L. lingua "tongue, speech, language;" O.Ir. tenge; Welsh tafod; Lith. liezuvis; O.C.S. jezyku; M.Du. tonghe; Du. tong; O.H.G. zunga; Ger. Zunge; Goth. tuggo; PIE base *dnghwa-) + -idan infinitive suffix. The similarity of tarâzabân with the classical Pers. terms tarzafân, tarzabân "a person who translates orally from one language into another; eloquent" is intriguing: from tar- variant of tarâ- + zafân, zabân "tongue, language"?!

1) Mechanics: A motion of a rigid body characterized by parallel paths of all particles. Every point of the body in translation has the same velocity and acceleration at any particular instant. The translation motion may be rectilinear or curvilinear.
2) Math.: A transformation which moves all points on a plane through the same distance in the same direction. The object and its image are congruent. Also a function obtained from a given function by adding the same constant to the value of each of its variables.
3) A rendering from one language into another; a version of such a rendering.

Verbal noun of → translate.

Tarâjâyeš, verbal noun of tarâjâyidan, tarâzabâneš, verbal noun of tarâzabânidan, → translate.

The quality of a material that allows light to pass through, but only diffusely, so that objects on the other side cannot be clearly distinguished. → transparent.

From L. translucent-, p.p. of translucere "to shine through," from → trans- + lucere "to shine," related to lux "light," lucidus "clear," luna, "moon;" Fr. lumière "light;" cf. Pers. ruz "day," rowšan "bright, clear," rowzan "window, aperture;" foruq "light," afruxtan "to light, kindle;" Mid.Pers. rôšn "light; bright, luminous," rôc "day;" O.Pers. raucah-rocânak "window;" O.Pers. raocah- "light, luminous; daylight;" Av. raocana- "bright, shining, radiant;" akin to Skt. rocaná- "bright, shining," roka- "brightness, light;" Gk. leukos "white, clear;" O.E. leoht, leht, from W.Gmc. *leukhtam (cf. O.Fris. liacht, M.Du. lucht, Ger. Licht), from PIE *leuk- "light, brightness."

Tarâtâb, from tarâ-, → trans- + tâb present stem of tâbidan "to shine," variants tâftan "to shine," tafsidan "to become hot;" Mid.Pers. tâftan "to heat, burn, shine;" taftan "to become hot;" Parthian t'b "to shine;" Av. tāp-, taf- "to warm up, heat," tafsat "became hot," tāpaiieiti "to create warmth;" cf. Skt. tap- "to heat, be/become hot; to spoil, injure, damage; to suffer," tapati "burns;" L. tepere "to be warm," tepidus "warm;" PIE base *tep- "to be warm."

A type of → interstellar medium cloud where → carbon (C), in → ionized atomic form and protected from → interstellar radiation, transforms into neutral atomic or molecular form. The chemistry in this regime is qualitatively different than in the → diffuse molecular clouds, both because of the decreasing electron fraction and because of the abundance of the highly reactive C atoms. The translucent cloud regime is the least well understood of all the cloud types. This is partly because of a relative lack of observational data, but also because theoretical models do not all agree on the chemical behavior in this transition region. In some models, there is a zone where the abundance of C exceeds that of C⁺ and CO; in others the peak abundance of C falls below that of C+ and CO. To cope with this uncertainty, Snow & McCall (2006) propose a working definition of translucent cloud material as gas with C⁺ fraction < 0.5 and CO fraction < 0.9. This definition reflects the fact that C+ is no longer the dominant form of carbon as it converts to neutral or molecular form, but also excludes the → dense molecular clouds, where carbon is almost exclusively CO (Snow & McCall, 2006, ARA&A 44, 367).

→ translucent; → cloud.

The space beyond the orbit of the Moon. Compare to → cislunar.

→ trans- + → lunar.

Ânsumâhi, ânsumângi, from ânsu "the other side," from ân "that" + su "side" + mâhi, mângi, → lunar; tarâ-, → trans-.

1) The act or process of transmitting. The fact of being transmitted.
2) The broadcasting of electromagnetic waves from one location to another, as from a transmitter to a receiver.

Verbal noun of → transmit.

The frequency range above the cutoff frequency in a waveguide or transmission line.

→ transmission; → band.

The ratio given by the → amplitude (or energy) of a transmitted wave divided by the amplitude (or energy) of the incident wave.

→ transmission; → coefficient.

A diffraction grating that has grooves ruled onto a transparent material so that a beam of light passed through the grating is partly split into spectral orders.

→ transmission; → grating.

A decrease in power in transmission from one point to another.

→ transmission; → loss.

An assembly of elements which are capable of functioning together to transmit power or signals.

→ transmission; → system.

To cause (light, heat, sound, etc.) to pass through a medium.

M.E. transmitten, from L. transmittere "send across, transfer, pass on," from → trans- "across" + mittere "to send."

Tarâgosilidan, infinitive of tarâgosli, from tarâ-→ trans- "across" + gosil "sending away, dismission," variant gosi; Mid.Pers. wisé "to despatch" (Parthian Mid.Pers. wsys- "to despatch;" Buddhist Mid.Pers. wsydy "to despatch;" Sogdian 'ns'yd- "to exhort"), from Proto-Iranian *vi-sid- "to despatch, send off," from prefix vi- "apart, away, out," + *sid- "to call."