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

The laws of physics should be the same if a particle is interchanged with its → antiparticle (→ charge conjugation), or swapped for its mirror image (→ parity symmetry). It is known that charge-parity (CP) symmetry holds for interactions involving → electromagnetism, → gravitation, and → strong interactions, but CP violation is known to occur during → weak interactions involved in → radio decay. Same as → CP-symmetry.

→ charge; → parity; → symmetry.

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

→ charge; → transfer; → device.

Fraction of the original charge which is successfully transferred from one pixel to the next in one CCD cycle.

→ charge; → transfer; → efficiency.

Quality of a → particle, → body, or → system that possesses → electric charge

Past participle of "to → charge."

Bârdâr "charged," from bâr, → cahrge, + dâr "having, possessor," from dâštan "to have, to possess," Mid.Pers. dâštan, O.Pers./Av. root dar- "to hold, keep back, maitain, keep in mind," Skt. dhr-, dharma- "law," Gk. thronos "elevated seat, throne," L. firmus "firm, stable," Lith. daryti "to make," PIE *dher- "to hold, support."

Any particle containing either a → positive or → negative → electric charge.

→ charged; → particle.

An → asteroid that belongs to the class of → Centaurs (discovered through stellar → occultation observations). At just 250 km across, Chariklo is the smallest body so far found to have rings. There are two dense rings, with respective widths of about 7 and 3 km, → optical depth of 0.4 and 0.06, and orbital radii of 391 and 405 km (see F. Braga-Ribas et al. Nature, 2014, 26 March).

From Khariklo, the name of a nymph in Greek mythology, the wife of → Chiron and the daughter of → Apollo.

The volume of a fixed mass of any gas increases for each degree rise in temperature by a constant fraction of the volume at 0° C, the pressure being constant throughout.

Named after Jacques Charles (1746-1823), French physicist, who first discovered the law, and who was responsible for the first balloon ascents using hydrogen.

The largest satellite of Pluto. It is about 1,040 km across, roughly half Pluto's diameter. Charon is unusual in that it is the largest moon with respect to its primary planet in the Solar System. Moreover, the Pluto-Charon system is extraordinary because the center of mass lies in open space between the two, a characteristic of a double planet system. Pluto and Charon are also tidally locked in a synchronous orbit. Pluto's rotational period is 6.39 Earth days. It takes 6.39 days for Charon to make one revolution around Pluto. Thus, the two bodies continuously face each other. Also called Pluto I.

In Gk. mythology, Xαρον (Charon) was a figure who ferried the dead across the river Styx into Hades (the underworld).

An elementary particle detector using a special apparatus capable of operating at high rates. The detector consists of an → array of many closely spaced parallel wires, or → anodes, in an enclosure filled with a carefully chosen gas. The wires, being placed between two → cathode plates, are under high voltage. Each wire acts as an independent → proportional counter. The particle that passes through the chamber will ionize surrounding gaseous atoms. The resulting ions and electrons are accelerated by the electric field around the wire, causing a localized cascade of ionization which brings about an electric current proportional to the energy of the detected particle. Previous detectors, such as the → bubble chamber, could record the tracks left by particles on photographic emulsions at the rate of only one or two per second. In comparison, the multiwire chamber records up to one million tracks per second in three dimensions with an accuracy of a tenth of a millimeter and moreover sends the data directly to a computer for analysis. The speed and precision of the multiwire chamber has revolutionized high-energy physics. For instance it was crucial in finding the predicted → W boson and → Z boson of the → electroweak interaction theory. Charpak's chamber also has applications in medicine, biology, and industry. Also called → multiwire proportional chamber.

In honor of Georges Charpak (1924-2010), a French physicist, who built the first detector of this type in 1968. He received the Nobel Prize for physics in 1992; → detector.

In astrogeology, long, narrow, steep sided depressions on planets and Moon, for example, Melas Chasma and Candor Chasma on Mars.

L. chasma, from Gk. khasma "yawning hollow, gulf," related to khaskein "to yawn," and thus to → chaos (1).

Karz "big fissure in a mountain," from Qâeni dialect.

A → meteor exploded on February 15, 2013 over Chelyabinsk, southern Russia.The explosion occurred at a height of 20 km above Earth, releasing 500 kilotons → TNT equivalent of energy, approximately 30 times the yield of the nuclear bomb over Hiroshima. It caused a → shock wave that damaged 7,200 buildings in six Russian cities and injured some 1,500 people, mainly from flying glass. Later, about five tons of meteoritic material reached the ground, including a 650 kg → meteorite that was recovered by divers from the bottom of Lake Chebarkul, on the slopes of the southern Ural mountains. With an estimated initial mass of about 12,000-13,000 metric tons, and measuring about 20 m in diameter, it is the largest known natural object to have entered Earth's atmosphere since the 1908 → Tunguska event.

Chelyabinsk, a city in Russia, the capital of the Chelyabinsk region, on the eastern slope of the Ural Mountains on the Miass River, 200 km south of Ekaterinburg and 1,879 km east of Moscow. The population of Chelyabinsk is about 1,183,000 (2015), the area, 530 sq. km; → meteor.

A combining form meaning "chemical, chemically induced, chemistry," used in the formation of compound terms like → chemosynthesis. Also chem- (before a vowel) and chemo-.

Chemi- extracted from → chemical or → chemistry.

Of, relating to, used in, or produced by means of chemistry.

From chemic "of alchemy," → chemistry + → -al.

Šimiyâyi, of or pertaining to šimi→ chemistry.
Šimik, from šim- + -ik, → -ic.

The relative amount of a given → chemical element or → chemical compound with respect to another element or compound in a given sample.

→ chemical; → abundance.

Same as → chemisorption.

→ chemical; → adsorption.

The extent to which a chemical species, such as an atom or molecule, tends to combine with another to form a chemical compound.

→ chemical; → affinity.

A force by which chemical substances are held together by attraction of atoms to each other through sharing, as well as exchanging, of electrons.

→ chemical; → bond.

The identities, and relative abundances of the → chemical elements or → compounds that make up a substance.

→ chemical; → composition.

A substance whose molecules are made up of atoms of at least two different elements.

→ chemical; → compound.

A substance which consists entirely of atoms of the same → atomic number and cannot be decomposed or changed into another substance using chemical means. Currently 118 chemical elements are known, the most abundant being → hydrogen. → periodic table.

→ chemical; → element.