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

A prefix meaning "old, ancient" especially in reference to former geologic time periods, e.g. → paleoclimatology, → paleolithic, and → paleomagnetism.

From Gk. palaio-, combining form of palaios "old, ancient," from palai "long ago, far back," from PIE root *kwel- "to turn, move about," also "far"

Pârin, pâriné "ancient," also "last year" (contraction of pâr sâl), related to pir "old;" Mid.Pers. pir "old, aged, ancient;" Av. parô (adv.) "before, before (of time), in front (of space);" cf. Skt. puáh, combining form of puras "before (of time and place), in front, in advance."
Dirin, diriné "old, ancient, of times past," from dir "old, antique; a long while" + suffix -in. The first component from Mid.Pers. dêr, variants dagr, drâz "long" (Mod.Pers. derâz "long," variant Laki, Kurdi derež); O.Pers. darga- "long;" Av. darəga-, darəγa- "long," drājištəm "longest;" cf. Skt. dirghá- "long (in space and time);" L. longus "long;" Gk. dolikhos "elongated;" O.H.G., Ger. lang; Goth. laggs "long;" PIE base *dlonghos- "long." The second component -in adj. suffix, from Mid.Pers. -ên (as in âhênên, zarrên), from Av. -aēna- (ayanhaēna- "made of iron," zaranaēna- "golden"); cf. Skt. -ēna-.

The climate during a past geologic time or before historical records.

→ paleo-; → climate.

The study of past → climates throughout → geologic and → historic time (paleoclimates), and the causes of their variations.

→ paleo-; → climatology.

A period of → geologic time lasting about 42 million years, roughly from 65 to 23 million years ago. The Paleogene is most notable as being the time in which mammals evolved from relatively small, simple forms into a large group of diverse animals in the wake of the → Cretaceous-Paleogene extinction event that ended the preceding → Cretaceous period. Birds also evolved considerably during this period, changing into roughly modern forms.

Literally "ancient birth," from → paleo- + -gene, → gene.

Of, pertaining to, or characteristic of the cultures of the Old Stone Age, marked by the earliest known chipped stone tools. The period continued from about 750,000 years ago, until the beginning of the Mesolithic Age, about 15,000 years ago.

→ paleo-; lithic, from Gk. lithos "stone."

The study of natural remanent magnetization in order to determine the intensity and direction of the Earth's magnetic field in the geologic past.

→ paleo-; → magnetism.

The study of ancient life through → fossils.

From Fr. paléontologie, from paléo-, → paleo-, + onto-, from Gk. ont- "being," pr.p. of einai "to be," + → -logy.

Pârin-šenâsi, from pârin-, → paleo- + šenâsi, → -logy.

The property of certain crystals of exhibiting different colors when viewed from different directions under transmitted light. This is because the degree with which certain birefringent crystals transmit polarized light is different, depending on whether the ray is ordinary or extraordinary. Pleochroism is the general term for both dichroism, which is found in uniaxial crystals (crystals with a single optic axis), and trichroism, found in biaxial crystals (two optic axes).

From pleochro(ic), from pleo- prefix meaning "more," from Gk. pleion "more," cognate with Pers. por, → full, + chroic, from chroos "skin, color" + -ism.

Candfâmi, from cand "so many, much; how many, how much" (O.Pers. yāvā "as long as;" Av. yauuant- [adj.] "how great?, how much?, how many?," yauuat [adv.] "as much as, as far as;" cf. Skt. yāvant- "how big, how much;" Gk. heos "as long as, until") + fâm "color," + -i noun suffix.

The formation of → chemical elements in the → early Universe, between about 0.01 seconds and 3 minutes after the → Big Bang, when the nuclei of primordial matter collided and fused with one another. Most of the → helium in the → Universe was created by this process. Same as → Big Bang nucleosynthesis

→ primordial; → nucleosynthesis.

The brightest star in the constellation → Leo (V = 1.35). Regulus is approximately 77.5 light-years from Earth. It is a triple star system composed of a hot, bluish-white star with a pair of small, faint companions. The main star (Regulus A) is a main sequence of type B7, with a luminosity 140 times brighter than the Sun. Its equatorial rotation speed being 317 kilometers per second, the fast rotation distorts Regulus into an oblate spheroid with an equatorial diameter about 30 percent larger than the polar diameter. As a result, the poles, with a temperature of 15,400 Kelvin, are much hotter than the equator, which glows at 10,200 Kelvin.

L., literally "little king," diminutive of rex "king," related to regere "to keep straight, guide, lead, rule," from PIE base *reg- "to rule, to lead straight, to put right;" akin to Pers. râst "right, straight, correct," → right.

Širdel, literally "the Lion's heart," on the model of Ar. Qalb al-Asad (قلب‌الاسد), from šir "lion;" Mid.Pers. šagr "lion" + del "heart;" Mid.Pers. dil; Av. zərəd- "heart;" cf. Skt. hrd-; Gk. kardia; L. cor Arm. sirt; PIE base *kerd- "heart;" O.E. heorte; E. heart; Ger. Herz; Bret. kreiz "middle."

A sickle-shaped → asterism forming the back of the Lion's head. It is marked by six stars: ε Leonis, μ Leonis, ζ Leonis, γ Leonis, η Leonis, and α Leonis (→ Regulus).

→ sickle; → Leo.

The → nuclear reaction process taking place inside stars, whereby → chemical elements are produced from pre-existing nuclei heavier than → hydrogen and → helium.

→ stellar; → nucleosynthesis.