# An Etymological Dictionary of Astronomy and AstrophysicsEnglish-French-Persian

## فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

### M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 8 Search : proper
 proper   سره   saré (#)Fr.: propre   Belonging or pertaining exclusively or distinctly to a person, thing, or group. → proper mass; → proper motion; → proper time.M.E., from O.Fr. propre, from L. proprius "one's own."Saré "pure; principal." proper distance   اپست ِ سره   apest-e saréFr.: distance propre   A distance between two nearby events in the frame in which they occur at the same time. It is the distance measured by a ruler at the time of observation. Hence, for a cosmological time t, Dproper = DC . a(t), where DC is the → comoving distance, and a(t) is the → scale factor. In the present epoch a = a(tobs) = 1, and Dproper = DC.→ proper; → distance. proper mass   جرم ِ سره   jerm-e saréFr.: masse propre   Same as → rest mass.→ proper; → mass. proper motion   جنبش ِ سره   jonbeš-e saréFr.: mouvement propre   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. proper motion distance   دورای ِ جنبش ِ سره   durâ-ye jonbeš-e saréFr.: distance mouvement propre   The distance derived from the → proper motion of an object. If an object has a known → transverse velocity  u, and has an observed angular motion of dθ/dt, then the proper motion distance is defined as: d = u/(dθ/dt).→ proper; → motion; → distance proper subset   زیرهنگرد ِ سره   zirhangard-e saréFr.: sous-ensemble propre   Of two sets A and B, the set A if it is contained in B (A ⊂ B) but is not equal to B (A ≠ B).→ proper; → subset. proper time   زمان ِ سره   zamân-e saré (#)Fr.: temps propre   In general relativity, the time as measured on a clock that travels with the observer in the same system. An accelerated clock will measure shorter time intervals between events than a non-accelerated clock between the same events. → twin paradox.→ proper; → time. property   داراک   dârâkFr.: propriété   1) General: An essential or distinctive attribute or quality of a thing. 2) Physics: A quantity, such as length, mass, pressure, temperature, or volume, that relates to the state of a system and can be expressed in numbers obtained from well-defined measurement operations.From M.E. propriete "ownership, something owned, one's own nature," from M.Fr. propriété, from L. proprietas "ownership, property, propriety," literally "special character," noun of quality from proprius "one's own, special."Dârâk "thing owned," from dâr present stem of dâštan "to have, to possess" + -âk (on the model of xorâk, pušâk, kâvâk). The first element dâštan, from Mid.Pers. dâštan, O.Pers./Av. root dar- "to hold, keep back, maintain, keep in mind;" Skt. dhr- "to to hold, keep, preserve," dharma- "law;" Gk. thronos "elevated seat, throne;" L. firmus "firm, stable;" Lith. daryti "to make;" PIE *dher- "to hold, support."