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

A period of 76 years after which the new and full moons would return to the same day of the solar year. This was intended as an improvement of the → Metonic cycle because the 6940 days of the Metonic cycle exceeded 19 years by about a quarter of a day, and exceeded 235 → lunations by a larger amount of time.

Named after Calippus of Cyzicus (about 370-300 BC), a Greek astronomer and mathematician.

The eighth of → Jupiter's known moons and the second brightest and the outermost of the four → Galilean satellites. With a diameter of 4800 km (0.38 Earths), Castillo is roughly the same size as Mercury. It orbits Jupiter in 16.689 days at a distance of 1,883,000 km from the planet, beyond Jupiter's main → radiation belts. It is the third largest moon in the entire solar system. Its mass is 10.76 × 10²² kg (about 1.5 Earth Moons) and its mean → surface temperature is -155 °C. The most prominent feature of Callisto is its craters, as it has the most craters of any object in the solar system. Due to its orbit being further away from Jupiter, it is not under the same → tidal heating influences as → Io, → Europa, or → Ganymede. Callisto's thin → atmosphere is composed of → carbon dioxide and likely some → molecular oxygen. Callisto is thought to have formed as a result of slow → accretion from the → protoplanetary disk of gas and dust that surrounded Jupiter after its formation.

Callisto, an attendant of Artemis in Greek mythology. Because of her love affair with Zeus, she was transformed into a bear by Artemis. According to another legend she was changed into a bear by the jealous Hera. Zeus transferred her to the heavens as the → constellation  → Ursa Major (great bear).

1) Thermodynamics: The amount of → heat, in the → CGS system, required to raise the temperature of one gram of water from 14.5 °C to 15.5 °C at standard pressure. It is equal to 4.1858 → joules, a quantity called the 15° calorie. Also called gram-calorie, small calorie.
2) Physiology: A unit used to express the heat output of an organism and the fuel or energy value of food. It is equal to one kilocalorie.

From Fr. calorie, from L. calor "heat," calidus "warm;" PIE base *kelə- "cold; warm;" Av. sarəta- "cold;" Mod.Pers. sard "cold, cool;" Skt. śiśira- "cold;" Ossetian sald "cold," Lith. šaltas "cold," silti "become warm;" Welsh clyd "cool."

The measurement of the amount of → heat involved in various processes, such as chemical reactions, changes of state, and formation of solutions.

From L. calori- "heat," combining form of calor, → calorie, + → -metry.

Garmâsanji, from garmâ  → heat + -sanji  → -metry.

1) To give birth to a calf.
2) Of a → glacier, to break off so as to give birth to an → iceberg. → glacier calving.

M.E. calven, O.E. (Anglian) *calfian, from → calf.

Gugidan, infinitive from gug "cow, bull," → cow.

A satellite of Saturn discovered in 1980 on the images taken by Voyager 1. It shares the same orbit as Telesto and Tethys at a distance of 294,660 km and turns around the planet with a period of 1.888 days. It is 34 x 22 x 22 km in size.

In Greek mythology, Calypso was a sea nymph and the daughter of the Titan Atlas.

The Giraffe. An extended but inconspicuous → constellation near the north celestial pole. Approximate position: R.A. 5 h, Dec. 70°; abbreviation Cam, genitive form Camelopardalis.

M.E., from Medieval L. camlopardus, from L. camelopardalis, from Gk. kamelopardalis, from kamelos "camel" + pardalis, pard "leopard" (because the giraffe has a head like a camel's and the spots of a leopard), from L. pardus, from Gk. pardos "male panther," from the same source (probably Iranian) as Skt. prdaku- "leopard, tiger, snake," and Pers. palang "panther."

Zarrâfé "giraffe," from Ar. zarafa, probably from an African language. This term is at the origin of this animal's name in European languages, via It. giraffa. The Pers. name of the animal is: šotor-gâv-palang, from Mid.Pers., composed of šotor "camel" + gâv "ox, bull, cow," → Taurus, + palang "panther."

1) An apparatus for recording the light from an object onto a sensitive material, such as film or CCD detector.
2) A device that converts optical images into electrical impulses.

Mod.L. camera obscura "dark chamber" from L. camera "vaulted room," from Gk. kamara "vault," cf. Av. kamarâ- "waist; vault" Mod.Pers. kamar "waist," Skt. kamarati "is vaulted;" PIE base *kam- "to arch."

Kadak "small room," from kad, kadé "room, chamber, habitation, vault, cell, cavern," Mid.Pers. katak, Av. kata- "(small) room, closet, (small) house," cf. Goth. hethjo "small room" O.S. kotici "cavern, nest," PIE *kot(os).

A 3.6 m optical/infrared telescope jointly owned and operated by the Canadian National Research Council (NRC), the French Centre National de la Recherche Scientifique (CNRS), and the University of Hawaii. It became operational in 1979. The observatory is located atop the summit of Mauna Kea, a 4200 m, dormant volcano located on the island of Hawaii. The Observatory headquarters is located in Waimea (also known as Kamuela by the US Postal Service). Situated at the low latitude of Hawaii (+19° 45'), there is a fairly large sky overlapping with that of the → European Southern Observatory (ESO)  → La Silla observatory (δ = -29° 15'). The point where an object is seen at the same → zenith distance from La Silla and from Mauna Kea, when it crosses the meridian, is δ =-5°. Taking into consideration also the difference in elevation between the observatories, the → declination at which one has equal air mass is moved down to δ =-18°. The extreme limit of observing from Mauna Kea is -60° (10° above horizon) but all programs below -20° are most efficiently carried out from ESO.

Canada, from the St. Lawrence Iroquoian word kanata, meaning "village" or "settlement;" France, from the L. Francia "country of the Franks;" Hawaii, named for Hawai'iloa, a legendary figure from Hawaiian mytholgy; → telescope.

To make void; revoke; annul.

M.E. cancellen, from M.L. cancellare "to cross out," from L. cancellare "to make like a lattice," from cancelli "lattice, grating."

Fâtaridan, from Sogd. fâtar "to remove, to set aside," from *fra-taraya-, from *tar- "to cross" (Cheung 2007), → trans-.

The Crab. The dimmest → constellation of the → Zodiac, located in the northern hemisphere at approximately R.A. 8 h and Dec. +20°. The main feature of the constellation is the open cluster → Praesepe (M 44). Abbreviation: Cnc; genitive form: Cancri.

Cancer,from L., from Gk. karkinos; PIE base *qarq- "to be hard" (like the shell of a crab); cf. Skt. karkatah "crab," karkarah "hard."
In Gk. mythology the Crab was sent by the goddess Hera to bite Hercules in the midst of the struggle with → Hydra, but Hercules crushed the crustacean with his heel. Hera rewarded the Crab by placing it in the → Zodiac.

Xarcang "crab," from Mid.Pers. karcang, cf. Lori qerženg from kar-, qer- + cang, ženg "claw." The component xar/qer may be related to Av. xruta-, xraoždva- "hard," as in xruždisma- "hard ground" (from xruždi- + zam-), and to the PIE *qarq- "to be hard." In that case, the Pers. term for crab would literally mean "hard claw."

→ Tropic of Cancer.

The → SI unit of → luminous intensity in a given direction; symbol cd. It is defined by taking the fixed numerical value of the → luminous efficacy of → monochromatic radiation of → frequency 540 × 10¹² Hz, K_cd, to be 683 when expressed in the unit lm W^-1, which is equal to cd sr W^-1, or cd sr kg^-1 m^-2 s³, where the kilogram, meter and second are defined in terms of → Planck's constant (h), → velocity of light (c), and Δν_Cs.

From L. candela, → candle.

1) An applicant or suitable person for a position.
2) An astronomical entity which is being considered for belonging to a special class of entities; e.g. → black hole candidate, → dark matter candidate, → supernova candidate.

From L. candidatus "clothed in white" (reference to the white togas worn by those seeking office), from candidus "shining white," from candere "to shine," cf. Skt. cand- "to shine," candra "bright; the Moon;" PIE base *kand- "to glow, to shine."

Nâmzad, literally "nominated," from nâm, → name, + zad, p.p. of zadan "to strike" (Mid.Pers. zatan, žatan, O.Pers./Av. jan-, gan- "to strike, hit, smite, kill," Skt. han- "to strike, beat," Gk. theinein "to strike," L. fendere "to strike, push," Gmc *gundjo "war, battle;" PIE *g^when- "to strike, kill").

1) A cylinder or block of wax, tallow, or other fatty substance with a central wick, which is burned to produce light.
2) A unit of luminous intensity, superseded by the → candela.

M.E., O.E. candel, from L. candela "a light, torch," from candere "to shine," candidus "shining white" (E. candidate); cf. Skt. cand- "to shine, to glow," candati "shines," candra- "shining, glowing, the Moon;" Gk. kandaros "coal;" PIE base *kand- "to glow, to shine."

Šam', loan from Ar.

The Hunting Dogs. A small → constellation in the northern hemisphere at approximate position: R.A. 7h, Dec. +40°. Abbreviation: CVn, genitive form: Canum Venaticorum.

L. Canes Venatic from canes, pl. of canis "dog" + venatici, pl. of venaticus "hunting." The constellation was created by the Polish astronomer Johannes Hevelius in his sky chart of 1687.

Tâzi "greyhound, hunting dog," originally "swift, fast," from tâzidan, tâxtan "to run, to assault, to chase," Av. tak- "to run," Skt. talki "he rushes at," O.S. techim "to run away," Lith. teku "to run, flow." Sagân-e Tâzi, from sagân pl. of sag "dog" → Canis Major + tâzi.

The Greater Dog. A → constellation in the southern hemisphere which contains → Sirius, the brightest star of the whole sky. Approximate position: R.A. 7 h, Dec. -20°; abbreviation CMa; genitive form Canis Majoris.

L. Canis Major, from canis "dog" (cf. Gk. kuon, Skt. svâ-, Av. spâ-, Pers. sag; PIE *kwon-) + Maior "larger," from L. major, irregular comp. of magnus "large, great" (cf. Gk. megas, Av. maz-, masan-, mazant- "great, important," Skt. mah-, mahant-, Mod.Pers. meh; PIE *meg- "great").
Canis Major is usually seen as one of the two hunting dogs of the hunter Orion. The other dog is Canis Minor, the Little Dog.

Sag-e Bozorg, from sag, see the above paragraph, + bozorg "large, great," Mid.Pers. vuzurg, O.Pers. vazarka- "great," Av. vazra- "club," Skt. vajati, vaja- "strength," vajra- "Indira's thunderbolt," L. vegere "to be lively," PIE *weg- "to be strong, be lively."

The Lesser Dog. A small → constellation in the equatorial region of the northern sky at approximately R.A. 7h 30m, Dec. +5°. It hosts the bright star → Procyon. Abbreviation CMi, genitive form Canis Minoris.

Canis Minor, from canis "dog" → Canis Major; L. minor "lesser, smaller," from PIE base *min- "small" (cf. Gk. meion "less, lesser," Skt. mi-, minati "to diminish."

Sag "dog," → Canis Major; kucak "small," from Mid.Pers. kok, kotak, kotah "small, short; child."

Canon of Eclipses. The most famous catalogue of solar and lunar eclipses. Published in 1887 by Theodor von Oppolzer, the catalogue contains the elements of all solar and lunar eclipses between 1208 BC and 2161 AD. It has been superseded by the calculations of F. Espenak and J. Meeus, Five Millennium Canon of Solar Eclipses: -1999 to +3000 (NASA/TP-2006-214141) and Five Millennium Canon of Lunar Eclipses: -1999 to +3000 (NASA/TP-2009-214172).

Canon, from L. canon, from Gk. kanon "a straight rod, a measuring rod, rule;" Ger. Finsternisse, plural from finsternis "eclipse; darkness," from finster "dark," M.H.G. vinster, O.H.G. finstar "dark" + -nis suffix forming abstract nouns, → -ness.

Fehrest "index, catalogue, canon," → index; gerefthâ plural of gereft, → eclipse.

1) General: Pertaining to, established by, or conforming to a canon, i.e. a law or a general rule (especially in ecclesiastical matters).
2) Math.: Relating to the simplest or standard form of a general function, equation, rule, etc.

M.M. canonicalis, from canonic(us), from L. canon, from Gk. kanon "a straight rod, a measuring rod, rule " + alis, → -al.

Hanjârvâr, from hanjâr "a mason's rule, any string or instrument used by builders in laying stones straight; rule, law, way, custom; a norm" + -vâr suffix meaning "having, endowed with; like, in the manner of."