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

Setting the axis of a telescope parallel to prime directions. In equatorial mounting, they are made parallel with the Earth's axis of rotation and the equator respectively. → collimation.

→ align; → telescope.

Arranged in a → straight line.

Past participle of → align.

A magnetic field whose lines of force are oriented along a particular direction or by a particular manner (axially, vertically; randomly, properly, etc.)

→ aligned; → magnetic field.

The fact of being in line or bringing into line.

Verbal noun of → align; → -ment.

The brightest of the seven stars that make up the → Big Dipper → asterism. Alioth shines at magnitude +1.77 from a distance of about 80 → light-years. It is a white star of → spectral type A0pCr. The spectrum of the star is characterized by abnormally strong lines of → chromium and → europium.

Alioth, from Aliot, from Ar. Alyat (الیه) "tail, buttocks".

Jown, from Ar. Jawn "black camel or horse".

The second brightest star in → Ursa Major and the end star in the handle of the → Big Dipper. Alkaid is a blue B3V main sequence star of apparent magnitude of 1.86 and lies at about 100 → light-years.

Alkaid "leader, chief," from Al-Qa'id al-Banat an-Na'ash "the leader of the daughters of the bier," from Banat "daughters" + Na'ash "bier". Banat an-Na'ash is the Ar. name of the constellation.

Qâed from Ar. Al-Qa'id.

A substance that dissolves in water to give hydroxide ions. A generic name for → bases.

M.E. alkaly, from M.fr. alcali, M.L. alkali, from Ar. al-qily (القلی) "salt wort," a plant growing in alkaline soils.

Qalyâ, loan from Ar., as above.

A spectral line produced by an → alkali metal.

→ alkali; → line.

Any of the chemical elements belonging to group A of the → periodic table, which burn vigorously in air; i.e. → lithium, → sodium, → potassium, → rubidium, → cesium, and → francium. Alkali metals have a → valence of one and are softer and less dense than other metals.

→ alkali; → metal.

Having the properties of an → alkali; having a → pH greater than 7.0.

From alkal(i) + -ine a suffix denoting "of or pertaining to," "of the nature of," "like."

From qalyâ, → alkali, + -yi adj. suffix.

Any of the metallic chemical elements belonging to group 2 of the → periodic table; i.e. → beryllium, → magnesium, → calcium, → strontium, → barium, and → radium. They are not found free in the nature because they are highly reactive.

→ alkaline; → earth; → metal.

Felez, → metal; qalyâyi, → alkaline; xâki "of or pertaining to soil," from xâk, → soil.

The whole quantity or amount.

M.E. al, plural alle; O.E. eall "all, every, entire;" cf. O.Fris., O.H.G. al, O.N. allr, Goth. alls.

Hamé- "all," variant hami "all the time, always;" Mid.Pers. hamâg "all," hamê "all the time, always;" Av. hama- "any;" cf. Skt. sama-"any, every, whichever;" Gk. amo-then "whichever;" Goth. sums "any;" O.N. sumr "any;" O.E. sum "some;" E. some.

A → survey that collects data on the whole sky. For example the infrared → Two Micron All Sky Survey (2MASS) and the X-ray → ROSAT All-Sky Survey.

→ all; → sky; → survey.

A "Large Number of Small Dishes" (LNSD) array designed to be sensitive for → commensal surveys of conventional → radio astronomy projects and → SETI targets at centimeter wavelengths. The ATA will consist of 350 6m-diameter → dishes when completed, which will provide an outstanding survey speed and sensitivity. In addition, the many → antennas and → baseline pairs provide a rich → sampling of the → interferometer  → uv plane, so that a single pointing snapshot of the array of 350 antennas yields an image in a single field with about 15,000 independent → pixels. Other important features of the ATA include continuous frequency coverage over 0.5 GHz to 10 GHz and four simultaneously available 600-MHz bands at the → back-end which can be tuned to different frequencies in the overall band. The ATA is a joint project of the Radio Astronomy Laboratory of the University of California, Berkeley, and the SETI Institute in Mountain View, CA. The ATA is now complete to 42 antennas. Highlights of the system are the frequency agility, the low background and → side lobes of the antennas, the wideband feed and input receiver, the analog fiber optical system, the large spatial dynamic range, the back-end processing systems and the overall low cost (see, e.g., Backer et al., 2009, arXiv:0908.1175.pdf).

Named after Paul G. Allen (1953-2018), an American business magnate, computer programmer, researcher, investor, and philanthropist. A donation of $11.5 million by his foundation in 2004 contributed to the development of the project.

1) The act of allying or state of being allied; the result of this action.
2) A union to advance the common interests of the members.

M.E., from O.Fr. aliance, from al(ier) "to ally," → alloy, + → -ance.

Hamdasti, literally "joining hand," from ham-, → com-, + dast, → hand, + -i noun suffix.

1) General: To assign or allot for a particular purpose.
2) Computers: To assign an amount of resource (disk, memory, CPU time, etc.) to a defined user.

From M.L. allocate imperative plural of allocare "allocate," from → ad- "to" + locare "to place," from locus "a place."

Teskidan, from tesk "portion, share, part, lot; a tax upon lands, tribute extracted," variants tešk, toxs (kardan) "distribute, divide;" loaned in Ar. tisq, tasq; tasu "a weight of four barley corns; the twenty-forth part of a weight;" Mid.Pers. tasû "the fourth part," loaned in Ar. tassûj, in Syriac tassûgâ "the fourth part; a measure;" ultimately Proto-Ir. *caçû-ka-; cf. Av. caθwarô, catur-, → four.

The act of allocating; the state of being allocated.

Verbal noun of → allocate.

One of two or more forms in which a → chemical element occurs, each differing in physical properties; e.g. → diamond and → graphite are allotropes of → carbon.

From allo-, combining form of Gk. allos "other, different;" cf. L. alius "else;" → alias + trope, from Gk. -tropos "a turn, way, manner," from tropein "to turn;" PIE base *trep- "to turn" (cf. L. trepit "he turns").

Degarvâr, from degar "other, another" (Mid.Pers. dit, ditikar "the other, the second;" O.Pers. duvitiya- "second;" Av. daibitya-, bitya- "second;" Skt. dvitiya- "second;" PIE *duitiio- "second") + -vâr denoting "resembling, like;" Mid.Pers. -wâr; Av. -vara, -var; cf. Skt. -vara.

A property of certain → chemical elements, as → carbon, → sulfur, and → phosphorus of existing in two or more distinct forms, known as → allotropes.

→ allotrope.

In solid-state physics, the range of energies which electrons can attain in a material.

P.p. of v. allow, from O.Fr. alouer "approve," from L. allaudare , compound of → ad- "to" + laudare "to praise."

Bând, → band; parzâmidé, p.p. of parzâmidan "to send through, permit, allow," from parzâm "permission," from par- "through" + zâm stem of zâmidan, Mid.Pers. zâmenidan "to send, lead;" → permit