Describing a medium in which certain physical properties are different in different directions.
anisotropic homogeneous cosmological model
model-e keyhânšenâxti-ye hamgen o nâ-izogard
Fr.: modèle cosmiologique homogène mais anisotrope
The process in which the entire → mass of → two colliding → particles, one of → matter and one of → antimatter, is → converted into → radiant energy in the form of → gamma rays. See also → annihilation operator.
L. annihilatus, p.p. of annihilare "to reduce to nothing," from ad- "to" + nihil "nothing," from ne- "not" + hilum "small thing, trifle"
Nâbudi, from nâ- "not" + bud "to be, exist," from budan "to be, exist" + -i noun forming suffix.
Fr.: opérateur d'annihilation
To make known publicly or officially; proclaim; give notice of (Dictionary.com).
M.E., from M.Fr. anoncer, O.Fr. anoncier "announce, proclaim," from L. annuntiare, adnuntiare "to announce, relate," literally "to bring news," from → ad- "to" + nuntiare "relate, report," from nuntius "messenger."
Âžâyidan, from prefix â- + Sogd., Munji žây- "to speak, to say," Yaghnobi žoy- "to read, sing," Yazghulami γay- "to call," Pers. (prefixed) afqân "lamentation, groaning;" Av. gā- "to sing," pairi.gā.vacah- "who sings the words around," bərəzi.gāθra- "singing high," gāθə- "song, gāthā;" cf. Skt. gā- "to sing;" O.Russ. gajati "to croak (ravens)"; Lith. giedoti "to sing" (Cheung 2007).
Covering the period of a year; occurring or happening every year or once a year.
Annual, from M.Fr. annuel, from L.L. annualis, blend of L. annuus "yearly," from annus "year" and L. annalis "yearly," from annus "year," from PIE *atnos, from *at- "to go" (Skt. a'tati "he goes, wanders").
Sâlâné, from sâl, → year, + âné "-ly".
Fr.: aberration annuelle
The apparent, small displacement in position of a star during the year due to the → aberration of starlight. It depends on the → celestial latitude, and its maximum value is about 20''.50. See also → constant of aberration; → aberration orbit.
annual apparent motion
jonbeš-e sâlâne-ye padidâr
Fr.: mouvement annuel apparent
Fr.: équation annuelle
An irregularity in the Moon's orbit, which can amount to 11 degrees in a period of one year. It results from the Sun's disturbing effect on the motion of the Moon due to varying distance between them.
Fr.: mouvement annuel
The annual apparent motion of the → Sun in the sky with respect to → fixed stars along the path called → ecliptic. The apparent annual motion is due to the → Earth's → revolution about the Sun. In the course of this motion, the Sun appears to shifts about 1° eastward per day.
Fr.: parallaxe annuelle
The difference in position of a star as seen from the → Earth and → Sun, i.e. the angle subtended at a star by the mean → radius of the Earth's orbit around the Sun. Same as → heliocentric parallax. Because the Earth revolves around the Sun, we observe the sky from a constantly moving position in space. Therefore, we should expect to see an annual effect, in which the positions of nearby objects appear to oscillate back and forth in response to our motion around the Sun. This does in fact happen, but the distances to even the nearest stars are so great that we need to make careful observations with a telescope to detect it. The annual parallax of the nearest star, → Proxima Centauri, is 0.762 arcsec, which is too small for our → acuity of vision.
Fr.: variation annuelle
Generally, the variation of a quantity over a year. In particular the yearly change in the right ascension or declination of a star, produced by the combined effects of the precession of the equinoxes and the proper motion of the star.
(Especially of laws or other established rules, usages, etc.) to make void or null; abolish; cancel; invalidate (Dictionary.com).
Ânulidan, from prefix â- + nul, → null, + -idan infinitive suffix.
Having the form of a → ring.
From Fr. annulaire or directly from L. annularis "pertaining to a ring," from annulus, diminutive of anus "ring."
Halge-yi, halqevâr, adj. from halqé, → ring.
Fr.: éclipse annulaire
A solar eclipse in which the Moon is close the → apogee and is, therefore, too small to cover the whole disk of the Sun, leaving a visible edge or ring of sunlight. An annular eclipse can last for 12m 30s at the most. See also → total eclipse.
Fr.: éclipse annulaire-totale
A solar eclipse that has both annular and total phases. Same as → hybrid eclipse.
The maximum phase of an → annular eclipse during which the Moon's entire disk is seen silhouetted against the Sun. Annularity is the period between second and → third contact during an annular eclipse. It can last from a fraction of a second to a maximum of 12 minutes 29 seconds (F. Espenak, NASA).
From Gk. anodos "way up," from → ana- "up" + hodos "way."
Ânod, loanword from anode as above.
Fr.: mois anomalistique
The time interval of 27.554 551 days (27d 13h 18m 33.2s), on average, between two successive passages of the Moon through the → perigee of its orbit.
Anomalistic from → anomaly.
Pirâzamini from pirâzamin, → perigee.