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

A → resonance line of → lithium at 6707.81 Å doublet 6707.76 and 6707.91 Å.

→ lithium; I for → neutral atom; → line.

A peculiar evolved star of spectral type G or M whose spectrum displays a high abundance of lithium.

→ lithium; → star.

The presence or not of the lithium absorption line at 6708 Å, which is considered to be a sufficient condition for → substellarity in → L dwarfs. It has been shown that any object with lithium absorption and → effective temperature less than 2670 K is a → brown dwarf. For a discussion of potential problems with the lithium test see Kirkpatrick et al. (1993, ApJ 406, 701).

→ lithium; → test.

A prefix meaning "stone," used in the formation of compound words.

From Gk. lithos "stone."

Lito-, loan from Gk., as above.
Sang-, from sang, → stone.

→ lithophile element.

→ litho-; → -phile.

In the → Goldschmidt classification, a → chemical element that shows an → affinity for → silicate phases and is concentrated in the silicate portion of the Earth (→ crust and → mantle). This group includes → lithium (Li), → beryllium (Be), → sodium (Na), → magnesium (Mg), → potassium (K), → calcium (Ca), → barium (Ba), → titanium (Ti), → chromium (Cr), → aluminium (Al), → silicon (Si), → phosphorus (P), → chlorine (Cl), etc.

→ lithophile; → element.

The solid portion of the → Earth, as compared to the → atmosphere and the → hydrosphere. The lithosphere consists of semi-rigid plates that move relative to each other on the underlying → asthenosphere. The process is known as → plate tectonics and helps explain → continental drift.

→ litho-; → sphere.

An asterism in the constellation → Ursa Minor. This group of stars ends at → Polaris, the pole star of the Northern Hemisphere.

Little, from M.E., O.E. lytel, from W.Gmc. *lutila- (cf. Du. luttel, O.H.G. luzzil, Ger. lützel, Goth. leitils), from PIE *leud- "small;" dipper, from dip, O.E. dyppan "immerse," from P.Gmc. *dupjanan.

Haft xâharân "the seven sisters," from haft "seven" (Mid.Pers. haft; Av. hapta; cf. Skt. sapta; Gk. hepta; L. septem; P.Gmc. *sebun; Du. zeven; O.H.G. sibun; Ger. sieben; E. seven; PIE *septm) + xâharân plural of xâhar "sister;" Mid.Pers. xwâhar "sister;" Av. x^vanhar- "sister;" cf. Skt. svásar- "sister;" Sogdian xwār; Gk. eor; L. soror (Fr. soeur); Arm. k'oyr; O.C.S., Rus. sestra; Lith. sesuo; O.Ir. siur; Welsh chwaer; M.Du. suster; Du. zuster; O.H.G. swester; Goth. swistar; Ger. Schwester; Swed. sister; Dan. søster; O.E. sweostor, swuster; E. sister.
Camcé "a spoon, ladle; a wooden bowl or cup;" kucak "small" (Mid.Pers. kucak "small"), related to kutâh "short, small, little," kudak "child, infant," kutulé, → dwarf, Mid.Pers. kôtâh "low," kôtak "small, young; baby;" Av. kutaka- "little, small").

A roughly 400-year period from the mid-16th through the mid-19th centuries when temperatures over much of Europe were unusually cold. Glaciers in the Alps advanced and European rivers froze much more often than during the past century. Harvests failed, livestock perished, and poor people suffered from famine and disease. The Little Ice Age coincided with two successive low → solar activity periods, the → Sporer minimum and the → Maunder minimum.

→ little; → ice; → age.

A prism having angles of 30, 60, and 90°, which uses the same face for input and dispersed radiation. The beam is reflected at the face opposite to the 60° angle because it is coated to be highly reflecting. A beam entering at the → Brewster angle undergoes minimum deviation and hence maximum dispersion. Littrow prisms are used in laser cavities to fine tune lasers by selection of wavelength.

Joseph Johann Littrow (1781-1840), Austrian astronomer; → prism.

An optical arrangement in which light from a source is allowed to fall on a plane mirror at → grazing incidence. The light directly coming from the source interferes with the light reflected from the mirror forming an → interference pattern. See also → Fresnel's biprism, → Fresnel's mirrors.

After the Irish physicist Humphry Lloyd (1800-1881); → mirror.

1) Something that is borne or carried.
2) Computers: To bring (a program or data) into main storage from external or auxiliary storage.
To place (an input/output medium) into an appropriate device, as by inserting a disk into a disk drive. See also: → download, → upload, → overload.

From M.E. lode, originally the same word as lode, from O.E. lāad "way, course, carrying;" cf. O.N. leith "way, route," O.H.G. leita "procession."

Bâr kardan "to load," composite verb from bâr "load, charhe, burden," (Mid.Pers. bâr, from O.Pers./Av. base bar- "to bear, carry;" Mod.Pers. bordan "to carry;" L. brutus "heavy, dull, stupid, brutish;" Skt. bhara- "burden, load," bharati "he carries;" Gk. baros "weight;" Mod.Pers. gerân "heavy;" Skt. guru; L. gravis; PIE *gwere- "heavy," *bher- "carry, give birth") + kardan "to do, to make" (Mid.Pers. kardan; O.Pers./Av. kar- "to do, make, build;" Av. kərənaoiti "he makes;" cf. Skt. kr- "to do, to make," krnoti "he makes, he does," karoti "he makes, he does," karma "act, deed;" PIE base k^wer- "to do, to make").

The act of a person or thing that loads. See also: → download, → upload.

Verbal noun of → load.

A surface feature on a planet or satellite in the form of a line of cliffs. Lobate scarps are formed when planetary or lunar mantle cools down and contracts inside. The loss of volume squeezes portions of the outer crust together. Eventually, the crust breaks and some of it is pushed up, creating long cliffs that look like wrinkles. Lunar scarps are generally tens of kilometers long and less than 100 m high. They have formed during the last billion years.

Lobate "having the form of a → lobe;" → scarp.

General: A roundish projection that is part of a larger structure.
Radioastronomy: In an antenna pattern, a region of local maximum in the emitted intensity. The strongest lobe is in the pointing direction of a directional antenna and is called the main lobe.
Quasar: One of the two lobe-like structures well apart from the central source, observed in radio images of some quasars. Same as radio lobe.

From M.L. lobus, from L.L. lobus "hull, husk, pod," from Gk. lobos "lobe of the ear, vegetable pod," probably related to leberis "husk of fruits;" from PIE base *lep- "to peel, flay."

Lap "lobe," variants lâp, lâb "piece, big piece, big cut," lappé "split pea; any of the two parts of a timber split through the length," maybe cognate with Gk. lobos, as above. Alternatively, related to Pers. las "loose," PIE *leu- "to loosen, divide, cut apart" (cf. Gk. lyein "to loosen, untie, slacken," lysus "a loosening;" L. luere "to loose, release;" → analysis).

The configuration of the response lobes of a radiotelescope.

→ lobe; → pattern.

A → radio-loud quasar in which the lobes dominate the whole emission. It has been conjectured that this phenomenon is an → orientation effect. If the → jet is close to the plane of the sky, the lobes will dominate. See also → core-dominated quasar.

→ lobe; → dominate; → quasar.

Pertaining to, characteristic of, or restricted to a particular place or particular places.
See also:
→ local arm, → Local Bubble, → Local Group, → local inertial frame, → local interstellar cloud, → local Lorentz invariance, → local maximum, → local meridian, → local oscillator, → local position invariance, → local sidereal time, → local standard of res, → Local Supercluster, → local thermodynamic equilibrium, → local time, → local Universe, → Local Volume, → localization, → localize, → non-local thermodynamic equilibrium.

From O.Fr. local, from L.L. localis "pertaining to a place," from L. locus "place."

Mahali, related to mahal "place, locality," from Ar.

One of the → spiral arms of the → Milky Way Galaxy which contains our → solar system. Same as → Orion Arm.

→ local; → arm.

A region of low density in the → interstellar medium surrounding the → Solar System. It extends at least 300 → light-years in most directions and encompasses the stars of the immediate → solar neighborhood. The Local Bubble contains a hot, million-degree ionized hydrogen gas that emits in → X-rays. → Neutral hydrogen has a density approximately one tenth of the average for the interstellar medium in the Milky Way. The bubble is thought to be a result of the → shock waves from → supernovae sweeping through the region within the past two to four million years.

→ local; → bubble.