A pair of forbidden spectral lines of the same atom arising from
a common upper excitation level, for example [O III] λ 5007 and
[O III] λ 4959, [N II] λ 6584 and [N II] λ 6548, and [S II] λ 6717,
[S II] λ 6731.
From O.Fr. doublet, from → double + -et diminutive suffix.
Dotâyé, from dotâ→ double + -(y)é nuance suffix.
dobâr-, dv-, dotâyi
Fr.: double, à ~
dobâr yonidé (#)
Fr.: deux fois ionisé
An atom that has lost two of its external electrons, for example O++ ([O III]).
doubly refracting crystal
bolur-e šakst-e dotâyi
Fr.: cristal à double réfraction
A → transparent → crystalline substance (such as calcite, quartz, and tourmaline) that is → anisotropic relative to the → speed of light. A ray incident normally on such crystals is broken up into two rays in traversing the crystal, → ordinary ray and → extraordinary ray.
gomân (#), šakk (#), dodeli (#),
1) A feeling of uncertainty about the truth, reality, or nature of something.
M.E. douten, from O.Fr. douter "doubt, be doubtful," from L. dubitare "to doubt, question, hesitate" (related to dubius "uncertain"), from duo, "→ two," + habere "have, hold," with a sense of "of having two minds, undecided between two things;" cf. Pers. dodeli, as below.
Gomân, from Mid.Pers. gumân "doubt;" ultimately from
Proto-Ir. *ui-man-, from suffixed *man- "to think,"
pâyin (#), foru
Fr.: en bas, vers le bas
M.E. doun, from O.E. dune "downward," short for adune, ofdune, from a-, of "off, from" + dune "hill."
Pâyin "bottom, below; at the foot of," from
pâ(y) "foot; step;" Mid.Pers. pâd, pây; Av. pad- "foot;" cf.
Skt. pat; Gk. pos, genitive podos; L. pes,
genitive pedis; E. foot; Ger. Fuss; Fr. pied;
Fr.: déclasser, dévaloriser
1) A downward slope, especially of a road.
1) bârgereftan; 2) bârgiri (#)
Fr.: 1) télécharger; 2) téléchargement
1) To transfer data from any other computer to one's computer.
A scenario of galaxy formation whereby massive galaxies formed earlier in the history of the → Universe (i.e. at high → redshifts) and completed their → star formation process more rapidly than low-mass galaxies. This scenario contrasts with what might be expected from simple → hierarchical structure formation scenarios, which predict that large galaxies formed in more recent times through the → merging of small galaxies.
Downsizing, first suggested by Cowie et al. (1996, AJ 112, 839), from downsize (v.), is a new sense for this term. Its current main meaning in non astrophysical contexts is "to make in a smaller size, or become smaller in size (in particular in economic vocabulary, by reductions in personnel)," from → down + → size.
Fr.: en aval
1) With or in the direction of the current of a stream. → upstream.
DQ white dwarf
sefid kutule-ye DQ
Fr.: naine blanche DQ
A → white dwarf whose spectrum shows carbon features of any kind.
The Dragon. A large constellation that winds around the north → celestial pole, appearing to encircle → Ursa Minor. The north → ecliptic pole also lies within Draco. Abbreviation: Dra, genitive form: Draconis.
O.Fr. dragon, from L. draco "serpent, dragon," from Gk. drakon "serpent, seafish," from drak-, strong aorist stem of derkesthai "to see clearly," perhaps literally "the one with the (deadly) glance," cf. Av. darəs- "to look," huuarə.darəsa- "having the appearance of the sun," Skt. darś- "to see, appear, look, show," dárśya- "worthy of being seen;" PIE base *derk- "to look."
Eždahâ, from Mid.Pers. aždahâg, ažidahâk, from Av. aži.dahāka- "the name of an evil king in the Iranian mythology," from aži- "serpent; dragon, monster" (Mid.Pers. až, âž, aži), cf. Skt. áhi- "snake, adder," Gk. ékhis, óphis "snake," L. anguis "snake," Arm. auj, Russ. už, Lith. angis; PIE base *angw(h)i- "snake, worm." The etymology of the second component, Av. dahāka-, is a matter of discussion. It is probably related to dahaka- "stinging, tormenting," from dah- "to sting, to do harm."
Fr.: Naine du Dragon
A dwarf elliptical galaxy that is a satellite of our Galaxy and lies at a distance of about 250,000 light-years from the Galactic center. Its diameter is only about 3,500 light-years, and its absolute magnitude -8.6, making it the least luminous galaxy known.
mâh-e gowzahri (#), ~ gerehi (#)
Fr.: mois draconitique
The time interval between two successive passages of the Moon through its → ascending node, 27.212 220 days (27d 5h 5 m 35.8s). Draconic month is important for predicting → eclipses. Also called draconitic month, nodical month.
Draconic, adj. of dragon, → Draco, referring to a mythological dragon for the following reason. Since an eclipse occurs when the Earth, the Sun, and a node are aligned and moreover the Moon is situated near the node, it was believed that a dragon that resided in the node swallowed the Sun or the Moon. → month.
Mâh, → month.
Two meteor showers with radiants in the constellation → Draco. One appears early in October and the other late in June.
1) kerré, 2) vârâné; 3) kerridan, kerrandan
Fr.: 1) traînée, entraînement; 2) traînée; 3) traîner
1) General: The act of dragging or the state of being dragged.
From O.N. draga, O.E. dragan "to draw," from P.Gmc. *dragan "to draw, pull," from PIE base *dhragh- "to draw, drag on the ground" (cf. Skt. dhrajati "pulls, slides in," L. trahere "to pull," Rus. drogi "wagon."
Kerr, kerré, kerridan "drag," cf. Laki keronen, Hamadâni kerândan
"to pull along, drag," Tâleši kernye, Tabari kərəš "to drag;"
Lori, Hamadâni kerr "line, scratch;" related to
Mid/Mod.Pers. kešidan, kašidan "to draw, protract,
trail, drag, carry;" kâštan, keštan, kâridan
"to cultivate, to plant, to make furrows;" Av. kar- "to strew seed,
cultivate," kāraiieiti "cultivates,"
karš- "to draw (a furrow), till, plant;"
cf. Skt. kar- "to scatter, strew, pour out," kars-, kársati
"to pull, drag, plow;" Gk. pelo, pelomai "to move, to bustle;"
PIE base kwels- "to plow."
Fr.: champ de Draine
Named after B. T. Draine, 1978, ApJS 36, 595.
Fr.: équation de Drake
A probabilistic argument used to estimate the number of
→ intelligent, communicating
→ extraterrestrial civilizations in the
→ Milky Way galaxy. The Drake equation is:
Frank Donald Drake (1930-); → equation.
Fr.: dragage, remontée
From M.E. (Scots) dreg-, O.E. draeg- (in drægnet "dragnet"), akin to dragan "to draw" + up.
Birunkašid, past stem of birun kašidan, from birun "out, the outside" (Mid.Pers. bêron, from bê "outside, out, away" + rôn "side, direction," Av. ravan- "(course of a) river") + kašidan "to draw," Mid.Pers. kašitan, Av. karš- "to draw," Skt. kars-, kársati "to pull, drag, plough," Gk. pelo, pelomai "to be busy, to bustle."