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

1) A regular or repetitive form, order, or arrangement; a distinctive form. → diffraction pattern; → interference pattern.
2) In the → density wave model, a region of enhanced stellar density (arm or bar) in the → Galactic disk. → pattern speed.

M.E. patron, from O.Fr. patron, from M.L. patronus "patron saint, lord, master, model, pattern," from pater "father."

Olgu "pattern," from Turkish ülgü "form, mold, model."

In models of → galactic structure, the → angular velocity of a → spiral arm or a → bar, assumed to be a pattern rotating as a solid body in the galaxy. Pattern speed, Ω_P , is one of the most important parameters of the → density wave theory responsible for the spiral arms. Pattern speed determines the location of the → corotation resonance.

→ pattern; → speed.

A quantum mechanical principle according to which no two identical → fermions can share the same → quantum state. Also known as → exclusion principle.

In honor of Wolfgang Pauli (1900-1958), Austrian theoretical physicist, who formulated the principle in 1925; → exclusion; → principle.

The Peacock. A → constellation in the → southern hemisphere, at about 19h 30m → right ascension, 65° south → declination. Abbreviation: Pav; genitive: Pavonis.

From L. pavo "peacock;" paupulo "peacock's sound;" Gk. taos "peacock;"

Tâvus, from Ar., ultimately from Gk. taos "peacock."

The round edible seed of a widely cultivated plant, Pisum sativum, of the legume family.

False singular from M.E. pease (plural pesen), from O.E. pise (West Saxon), piose (Mercian) "pea," from L.L. pisa, variant of L. pisum "pea," from Gk. pison "the pea."

Noxod "pea," from Mid.Pers. naxôd, naxvat "pea."

1) The normal, non warring condition of a nation, group of nations, or the world.
2) (often initial capital letter) An agreement or treaty between warring or antagonistic nations, groups, etc., to end hostilities and abstain from further fighting or antagonism.
3) A state of mutual harmony between people or groups, especially in personal relations.

From M.E. pes, pais, pees, from Anglo-Norman peis, pes, from O.Fr. pais "peace, reconciliation, silence," from L. pacem (nominative pax) "compact, agreement, treaty of peace, tranquility," ultimately from PIE root *pag- "to fasten."

Râman, related to râmeš "tranquility, rest," ârâm "quiet, peaceful," ârâmidan "to become calm, calmed, rest," Mid.Pers. râm "peace," râmenidan "to give peace, pleasure," râmišn "peace, pleasure;" Av. ram- "to stay, rest;" cf. Skt. ram- "to stop, stand still, rest, become appeased;" Gk. erema "quietly, gently;" Goth. rimis "rest;" Lith. rāmas "rest." + suufix -an.

The pointed top of a mountain or ridge. The pointed top of anything. → Gamow peak; → peak wavelength.

Perhaps from M.L.G. pék "pick, pike."

Setiq "summit, top," from *us-tig, from us-, → ex-, + tig "pointed," related to tiq "blade," tiz "sharp," tež, tej, tij; Mid.Pers. tigr, têz, têž "sharp," O.Pers. tigra- "pointed," tigra.xauda- "pointed helmet (epithet of Scythians)," Av. tiγra- "pointed," tiγray- "arrow," tiži.arštay- "with the pointed spear," cf. Skt. tikta- "sharp, pungent, bitter," tejas- "sharpness, edge, point or top of a flame;" PIE base *st(e)ig- "to stick; pointed." Cognates in other IE languages: Gk. stizein "to prick, puncture," stigma "mark made by a pointed instrument," L. in-stigare "to goad," O.H.G. stehhan, Ger. stechen "to stab, prick," Du. stecken, O.E. sticca "rod, twig, spoon," E. stick.

The → bolometric luminosity of a → supernova corresponding to the highest brightness in its → light curve. The peak luminosity occurs after the → supernova explosion; it is directly linked to the amount of radioactive ⁵⁶Ni produced in the explosion and can be used to test various explosion models. Following → Arnett's rule, one can derive the ⁵⁶Ni mass from the peak luminosity of a → Type Ia supernova.

→ peak; → luminosity.

The wavelength at which the radiant intensity of a source is maximum.

→ peak; → wavelength.

The pod or the enclosed edible seed of the plant, Arachis hypogaea, of the legume family: the pod is forced underground in growing, where it ripens (Dictionary.com). → box-peanut bulge.

From pea, → green pea galaxy + nut O.E. hnutu, akin to L. nux, → nucleus.

A secretion consisting mainly of calcium carbonate, CaCO₃, produced by various mollusks.

M.E. perle, from O.Fr. perle, M.L. perla of unknown origin.

Morvârid "pearl;" Mid.Pers. murwârid, murgârid; cf. Sogd. marγārit, marrγārt; Khotanese mrāhe. Gk. margarites "pearl" may be a loanword from Iranian.

A partially carbonized vegetable matter, usually mosses, found in bogs and used as fertilizer and fuel.

M.E. pete, of unknown origin.

Turb, from Fr. tourbe, from Germanic turba; cf. O.Fris. turf, O.H.G. zurba, Ger. Torf, O.E. turf, tyrf "slab of soil and grass," E. turf.

In astronomy, designating an object with special properties that deviates from others of its type.
Linguistically related terms: → particular, → special.

From L. peculiaris "of one's own (property)," from peculium "private property," from pecu "flock, farm animals, cattle," pecunia "money, property;" cf. Av. pasu-, fšu- "sheep;" Mid.Pers. pâh, pasvīk "cattle;" Mid./Mod.Pers. šu/ša in šupân/šabân "cattle keeper, shepherd;" Pers. dialects Laki and Tâti pas "sheep;" Skt. paśu- "cattle;" Goth. faihu "money, fortune;" O.E. feoh "cattle, money;" Ger. Vieh "cattle;" Lith. pekus "cattle;" PIE base *peku- "cattle."

Afd "peculiar; strange" (Dehxodâ), from Mid.Pers. afd, awd "peculiar, strange."

An irregular galaxy that has an abnormal shape (neither elliptical, spiral, nor lenticular) and/or has another unusual characteristic.

→ peculiar; → galaxy.

1) The true motion of a star with respect to the Local Standard of Rest. → proper motion.
2) The motion of a cosmological object other than the apparent recession caused by the expansion of the Universe.

→ peculiar; → motion.

A star with a spectrum that cannot be conveniently fitted into any of the standard → spectral classifications.

→ peculiar; → star.

1) Velocity with respect to the Local Standard of Rest.
2) Any velocity a galaxy has with respect to us that is not a Hubble law velocity due to the expansion of space.

→ peculiar; → velocity.

The quality or condition of being peculiar.

Noun form of → peculiar.

The Winged Horse. A large constellation in the northern hemisphere at 22h 50m right ascension, 20° north declination. The stars → Markab, → Scheat, and → Algenib form three corners of the famous Great → Square of Pegasus, which is completed by the star → Alpheratz from neighboring → Andromeda. Abbreviation: Peg; Genitive: Pegasi.

In Gk. mythology, Pegasus is the winged horse that was fathered by Poseidon with Medusa. When the head of Medusa was cut off by Perseus, the horse sprang forth from her pregnant body. Pegasus aided Perseus in his fight against both the Chimera and the Amazons.

Pegâsus, from Gk., as above; asb-e bâldâr "Winged Horse," referring to the Gk. mythology, from asb→ horse; bâl, → wing; dâr "having, possessor" (from dâštan "to have, to possess," Mid.Pers. dâštan, O.Pers./Av. root dar- "to hold, keep back, maintain, 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").

To make worse; to cause to deteriorate. To endow (a word) with a less favorable meaning.

Back formation from → pejorative.

Pastârdan, literally "to render low, vile, bring down" from past "low, vile, abject," → platykurtic, + ârdan, short for âvardan, "to cause or produce; to bring," → cause.