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

The point in the → Galactic plane that lies directly opposite the → Galactic center. It lies in → Auriga at approximately R.A. 5h 46m, Dec. +28° 56'; the nearest bright star to it is → Alnath in → Taurus.

Anticenter, from → anti- + → center.

Pâdmarkaz, from pâd-, → anti-, + markaz, → center.

1) An agreement between opposing armies to stop fighting for a particular time, especially in order to discuss possible peace; truce
2) A formal agreement, especially between nations, to end combat.

From Fr. armistice, from L. arma "arms" + -stitium, from sistere "to cause to stand," → solstice.

Nâjangân, literally "state of no war," from nâ- "no, not," → un-, + jang, → war, + -ân suffix of time and place.

→ Coma Berenices.

A → microwave → polarimeter designed specifically to target the → B-mode signature of → inflation in the → cosmic microwave background polarization. BICEP2 observed from the South Pole for three seasons from 2010 to 2012. This 26 cm aperture → telescope comprised an all-cold refracting optical system equipped with a → bolometer array of 512 → detectors (256 pixels) operating at 150 GHz.

BICEP2, the upgraded version of the first BICEP, short for Background Imaging of Cosmic Extragalactic Polarization.

A solid-state detector that stores the electrons, produced by incident photons, in potential wells at the surface of a semiconductor. The packages of charge are moved about the surface by being transferred to similar adjacent potential wells. The wells are controlled by the manipulation of voltage applied to surface electrodes.

→ charge; coupled adj. from → couple; → device.

A charge-transfer device that passes along stored charges positioned at predetermined locations; it is used as an image sensor in which the image points are accessed by reference to their horizontal and vertical coordinates.

→ charge; → injection; → device.

A semi-conductor device that relays stored charges positioned at predetermined locations, such as charge-coupled or charge-injection devices.

→ charge; → transfer; → device.

Berenice's Hair. A → constellation made up of many faint stars and located near the north Galactic pole between → Canes Venatici to the north, → Virgo to the south, → Leo to the west, and → Boötes to the east. Abbreviation: Com; genitive: Comae Berenices.

→ coma; L. Berenices genitive of Berenice, a queen of Egypt, wife of Ptolemy III, who sacrificed her hair to Aphrodite, begging her husband's victory in the war with the Assyrians, who had killed his sister. While the story is an old one, the constellation is relatively new, being introduced by Tycho Brahe (1546-1601).

Crystallography: The crystal structure of a → coordination compound.

→ coordination; → lattice.

The network of the points in space at which the atoms, molecules, or ions of a → crystal are regularly repeated.

→ crystal; → lattice.

Something, thought out, invented, or adapted, for a special purpose.
Assembly of parts or pieces in one body to perform a work, observe a phenomenon, or for measuring.

From O.Fr. devis "division, separation, disposition, wish," from L. divisus, p.p. of dividere "to divide," → divide.

Dastgâh "means, implement, apparatus," originally "wealth, splendour," from dast "strength, superiority," originally "hand" (Mid.Pers. dast, O.Pers. dasta-, Av. zasta-, cf. Skt. hásta-, Gk. kheir, L. praesto "at hand," Arm. jern "hand," Lith. pa-žastis "arm-pit;" PIE *ghes-to-) + gâh "place, time," O.Pers. gāθu-, Av. gātav-, gātu- "place, throne, spot" (Skt. gâtu- "going, motion; free space for moving; place of abode," PIE *gwem- "to go, come").

Interstellar ice grains with graphite, silicates, or other chemical compounds adsorbed on their surfaces.

→ dirty; → ice.

A model for a → cometary nucleus proposed by Fred Whipple (1950-51), according to which the nucleus is a solid body (a few kilometers across) made up of various → ices (→ frozen water, → methane, → ammonia, → carbon dioxide, and → hydrogen cyanide) in which → dust is embedded. Dust particles are liberated when the ices vaporize as the → comet approaches the → Sun, and they get blown away by → solar radiation pressure, often forming impressive, gently curved → dust tails.

→ dirty; → ice; → ball; → model.

The point in the → Galactic plane that lies directly opposite the → Galactic center. It lies in the constellation → Auriga at approximately R.A. 05h 46m, Dec. +28° 56'.

→ galactic; → anticenter.

1) The solid form of water; it is found in the atmosphere as snow crystals, hail, ice pellets, etc., and on the Earth's surface in forms such as frost, rime, glaze, glacier ice, etc.
2) The solid, frozen form of gases in cold astronomical objects.

Ice, from O.E. is "ice," from P.Gmc. *isa-; cf. O.N. iss, O.Fris. is, Du. ijs, Ger. Eis. Cognate with Pers. yax, as below.

Yax, from Av. aexa- "ice, frost," isav-, isu- "icy, chilly;" cf. Sarikoli (Pamir dialect) īš "cold;" P.Gmc. *isa-, as above.

Meteo.: The process by which a layer of ice builds up on solid objects that are exposed to freezing precipitation or to supercooled fog or cloud droplets.

→ ice; → accretion.

A major interval of geologic time during which extensive ice sheets (continental → glaciers) formed over many parts of the world. There have been at least five significant ice ages in Earth's history, with approximately a dozen epochs of glacial expansion occurring in the past 1 million years. The last one ran from about 75,000 to 15,000 years ago.

→ ice; → age.

A tiny particle of ice within which → water molecules are all lined up in a precise → crystalline structure. Ice crystals come in various shapes including needles, → dendrites, hexagonal columns, and → platelet. If the temperature decreases the water molecules can crystallize, arranging themselves around the suspended impurities such as dust particles. See also → snow crystal.

→ ice; → crystal.

A member of the lesser mass group of → gas giants. Ice giants contain a higher quantity of materials that form ices at low temperatures, such as → water, → methane, and → ammonia. There are two ice giants in the Solar System, → Uranus and → Neptune.

→ ice; → giant.

A building for storing ice throughout the year, mainly used prior to the invention of the refrigerator.

→ ice; → house.

Yaxcâl, literally "a pit of ice," but "any place or vessel in which ice is kept," from yax, → ice, + câl "pit, → hole."