An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 16 Search : tail
antitail
  پاددم   
pâddom

Fr.: contre-queue   

A small tail-like structure on a comet that, unlike most comet tails, seems to point toward the Sun. This rare event is an optical illusion due to larger dust particles left along the comet's orbit. And typically occurs when the Earth crosses the plane of the comet's orbit. It seen when the observer is in the plane of the cometary orbit.

Antitail, from → anti- "opposite, opposing, against" + → tail.

Pâddom, from pâd-, → anti-, + dom "tail."

cometary tail
  دم ِ دنباله‌دار   
dome- donbâledâr

Fr.: queue de comète   

A formation of → gas and/or → dust that streams away from the → coma of many comets under the influence of the Sun's → radiation pressure and the → solar wind. See also: → dust tail, → gas tail, → ion tail, → plasma tail, → sodium tail, → Type I tail, → Type II tail, → antitail.

cometary; → tail.

detail
  ۱) پازه؛ ۲) پازیدن   
1) pâzé; 2) pâzidan

Fr.: 1) détail; 2) détailler   

1) An individual or minute part; an item or → particular.
2) To relate or report with complete particulars; tell fully and distinctly (Dictionary.com).

From Fr. détail, from O.Fr. detail "small piece or quantity," literally "a cutting in pieces," from detaillier "to cut in pieces," from → de- "entirely" + taillier "to cut in pieces," from L. taliare "to split."

Pâzé, from Sogd. pâzê "portion, bit;" Kurd. pâž "part of a whole;" related to Mod.Pers. baxš "part, division," bâž "tribute, toll, impost;" ultimately from Proto-Ir. *baj- "to bestow, divide, have a share;" cf. Av. baž- (baxš-) "to divide, bestow, give a share;" O.Pers. bāji- "tribute, tax;" Mid.Pers. bâj, bâž "tribute, tax," baxtan "to distribute," baxt "luck, fate;" Skt. bhaj- "to share, distribute, apportion," Gk. phagein "to eat (to have a share of food)"; PIE base *bhag- "to share out, apportion;" → division.

detailed
  پازه‌مند   
pâzemand

Fr.: détaillé   

1) Having many details.
2) Thorough in the treatment of details (Dictionary.com).

Adjective from → detail.

dust tail
  دنباله‌ی ِ غباری   
donbâle-ye qobâri (#)

Fr.: queue de poussière   

The tail of a → comet which is caused by → solar radiation pressure forcing the dust particles away from the → coma in a curved arch. Also called a → Type II tail.

dust; → tail.

gas tail
  دنباله‌ی ِ گازی   
donbâle-ye gâzi

Fr.: queue de gaz   

The → ionized component of a → comet's → tail, driven nearly straight away from the → Sun Sun by the → solar wind. solar wind. Also called → ion tail, → plasma tail, and → Type I tail.

gas; → tail.

head-tail galaxy
  کهکشان ِ "سر-دم"   
kahkešân-e sar-dom

Fr.: galaxie tête-queue, ~ têtard   

A member of the class of radio galaxies (→ radio galaxy) that have a strong radio emission coming from a bright "head" and a more diffuse emission from a "tail." They are often found in clusters.

head; → tail; → galaxy.

ion tail
  دنباله‌ی ِ یونی   
donbâle-ye yoni (#)

Fr.: queue d'ions   

Of a comet, same as → gas tail.

gas; → tail.

magnetotail
  مغنات‌دُم   
meqnâtdom

Fr.: queue magnétique   

The portion of a planet's → magnetosphere which is pushed away from the Sun by the solar wind. Earth's magnetosphere extends about 65,000 km on the day-side but more than 10 times further.

From → magneto- + → tail.

neutral tail
  دم ِ نتار، دنباله‌ی ِ ~   
dom-e natâr, donbâle-ye ~

Fr.: queue neutre   

Same as → sodium tail.

neutral; → tail.

plasma tail
  دنباله‌ی ِ پلاسمایی   
donbale-ye plâsmâyi

Fr.: queue de plasma   

The ionized component of a comet's tail, driven nearly straight away from the Sun by the solar wind. Also called ion tail and gas tail.

plasma; → tail.

sodium tail
  دم ِ سودیومی   
dom-e sodiomi

Fr.: queue de sodium   

1) A kind of → cometary tail appearing in some → comets, such as → Hale-Bopp. Sodium tails arise from the very strong → fluorescence of their sodium atom → D lines in the visible. They are rapidly accelerated to high velocities by the Sun, forming a very straight tail distinct from the → ion tail. The release mechanism of sodium from comets is still a matter of debate. Also called → neutral tail.
2) An enormous, comet-like tail of sodium gas stretching out behind the Moon, at least 800,000 km (many hundreds, and perhaps thousands, of lunar radii). The tail is due to the strong influence of the Sun's → radiation pressure on sodium atoms (→ D line) present in the → lunar exosphere. Near → new Moon phase, the extended lunar sodium tail can be observed as it sweeps over the Earth and is gravitationally focused into a visible sodium "spot" in the → anti-solar direction. It is too faint to be detected by the human eye.

sodium; → tail.

tail
  دم، دنباله   
dom (#), donbâlé (#)

Fr.: queue   

1) The part that sticks out at the back of an animal's body, and that it can move.
2) Anything resembling such an appendage in form or position.
3) → cometary tail.

M.E.; O.E. tægl, from P.Gmc. *tagla- (cf. O.H.G. zagal, Ger. Zagel "tail," O.N. tagl "horse's tail").

Dom, variant domb, "tail;" Mid.Pers. dumb "tail;" Av. duma- "tail"; donbâlé, from domb + -âlé, -âl resemblance suffix, → -al.

tidal tail
  دنباله‌ی ِ کشندی   
donbâle-ye kešandi

Fr.: queue de marée   

A long stream of stars and gas, often in the form of a spectacular tail, thrown off a galaxy when it collides with another galaxy. → interacting galaxies; → merger. Two tidal tails form in each galaxy, and they are more spectacular when the masses of the two galaxies are comparable, and when their relative orbit is in the same sense as the rotation inside each spiral galaxy.

tidal; → tail.

Type I tail
  دم ِ گونه‌ی ِ I   
dom-e gune-ye I

Fr.: queue de type I   

The → gas tail of of a comet.

type; → tail.

Type II tail
  دم ِ گونه‌ی ِ II   
dom-e gune-ye II

Fr.: queue de type II   

The → dust tail of a → comet.

type; → tail.