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

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

   Homepage   
   


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

<< < -es -it -sc 201 951 abe abs abs aca acc acc aco act ada adh ado aer aft air Alf alg alk alp Alt alt amb ana And ang ani ann ant ant ant apo app app Apu arc arg Arn art ass ast ast ast atm ato att aur aut avo azi bac bal bar bar bat Bea Bel bet bia big bin bio Bir bla bla blo Blu bol Boo bou box bre Bri bro bur cal cal Can cap car Car cat cau cel cen cen cha Cha cha che Chi chr cir cir civ cla clo clo CMB coa coe coh col col col com com com com com com com com Com con con con con con con con con con con con con coo cor cor cor Cos cos cos cou cou cra cri cro cry cul cur cyc D l dar dat day dea dec dec dec def def deg Del Den dep der det deu dew dic dif dif dil dip dir dis dis dis dis dis diu dog Dop dou Dra Dsc dus dwa dyn Dys Ear ecc eco edg egg Ein Ela ele ele ele ele ell eme emp enc eng ent epi equ equ equ eru eth Eur eve exa exc exe exi exo exp ext ext ext fab fai Fan fea fem fer fie fil fir fir fla fli flu foc for for for fra fre fre fri fun fuz gal gal gal Gam gau Gau gen geo geo geo geo Gib glo gov gra gra gra gra gre gro Gui H-a hal Ham har Hay hea hei hel Hel her het hie hig hoa hom hor hot Hub Hug hur hyd hyd hyl hyp ice ide ima ima imp imp inc inc ind ine inf inf inf ing inn ins ins int int int int int int int int inv inv ion iro Isl iso iso Jab jet Jov Jup Kar Kep kil Kip Kra Lag Lam Lan Lar las law lea Leg Leo lev lig lim lin lin lin lit loc loc log Lor low lum lun lun Lym Mac mag mag mag mag mag mai Mal map mas mas mat Mau mea mea med Men mer Mes Met met mic mic Mie mil min Mir mix mod mol mom Moo mor mov mul mur n-b nan nat nea neg Ner neu new New NGC noc nom non non nor nor nuc nuc nul nut obj obl obs occ oct off old one ope opp opt opt orb ord org Ori osc oth ove Owl P-s Pal par par par par Pas pat pec pen per per per per per Pha pha pho pho pho phy pie pix Pla pla pla pla Pli Poi pol pol pol pol por pos pos pow pre pre pre pre pri pri pri pro pro pro pro pro pro pro pub pul pyc qua qua qua qua qui rad rad rad rad rad rad rai ran rar Ray rea Rea rec rec red red ref ref reg rel rel rel ren res res res res ret rev Ric rig rin roc roo rot rot rur S5- Sal sat sca sca Sch sci Scu sec sec sed sel sel sem seq set sha she sho sid sie sil sim sin sit sky slo sno sod sol sol sol sol son sou spa spa spe spe spe spe sph spi spo squ sta sta sta sta ste ste ste Sti sto str str sub sub sub sul sup sup sup sup sur sur syl syn sys tal Tay tel ten ter tex the the the the Tho thr tid tim Tit too Tor tra tra Tra tra Tra tri Tri tru tub tur two Typ ult ult unc uni uni uni upl ura uti val var vec vel ver Ver vie vir vis vis vol W-R war wav wav wea Wei wha wid win WN3 Wol wri xen yok zen zij > >>

Number of Results: 13176 Search : in
Guitar nebula
  میغ ِ گیتار   
miq-e gitâr

Fr.: nébuleuse de la Guitare   

A nebula resembling a guitar produced by a → neutron star, which is travelling at a speed of 1600 km per sec! The neutron star leaves behind a "wake" in the → interstellar medium, which just happens to look like a guitar (only at this time, and from our point of view in space). The Guitar Nebula is about 6.5 light years away, in the constellation → Cepheus, and occupies about an arc-minute in the sky, corresponding to about 300 years of travel for the neutron star.

Guitar, ultimately from Gk. kithara "cithara," a stringed musical instrument related to the lyre, perhaps from Pers. sehtar "three-stringed," from "three" + târ, → string. → nebula.

gulf
  خلیج   
xalij (#)

Fr.: golfe   

A deep → inlet of the sea almost surrounded by land, with a narrow mouth; a large deep → bay (OxfordDictionaries.com).

M.E. go(u)lf, from O.Fr. golfe, from It. golfo, from Gk. Gk. kolpos "bay, gulf of the sea," originally "bosom."

Xalij, ultimately from Proto-Ir. *garika-, from *gar- "to soak, moisten" (+ relation suffix -ika-, → -ics; notably the variant Tabari -ij, as in Yušij); cf. Gilaki *xal-, xâlə "stream, brook" (as in the stream names Cam.xâlə, Zât.xâlə, Hašu.xâlə, etc.), Tabari câl in Câlus (name of a river in Mâzandarân); Laki cal.ow "marsh;" Tabari kela, kila "stream;" Baluci kor "river;" Iranian rivers Kor (in the Fârs Province), Kârun and Karxé (both in Xuzestân); in classical Pers. literature kul, kul.âb "pond, reservoir," (prefixed far-) far.qar "a minor stream derived from a more considerable one; the bed of a river when almost dry, the small quantity of water remaining in such a river" (Steingass); âqâridan, âqeštan, farqâridan "to moisten, wet, macerate;" Dari Yazd qeriz "saliva;" Râvar, Bardsir, Kerman geriz "saliva;" Laki xur "swamp;" Tâti xer "cloud;" Bandare Jâski gerâh "moisture;" Ossetic I. qaryn/qard "to permeate, seep through (of liquid);" Shughni (prefixed) ažär- "to soak, wet;" Roshani (prefixed) nižêr-/nižêrd "to soak, wet;" Skt. gal- "to drip;" O.H.G. quellan "to well, to gush;" Ger. Quell, Quelle "source." Note that, according to the classical Pers. dictionary Borhân-e Qâte' compiled in India (17th century), xalij is a Pers. word and not Arabic. Similarly, M.A. Emâm-Shushtari, in his "Dictionary of Persian Words in Arabic," remarks that the Arabic root XLJ is irrelevant to the "gulf" sense.

gully
  آبکند   
âbkand (#)

Fr.: ravin   

A trench or ravine worn away by running water in the earth.

Gully, a variant of M.E. golet "water channel," from O.Fr. goulet, dim. of goule "throat, neck," from L. gula; cf. Mod.Pers. galu "throat," geri, geribân "collar," gerivé "low hill," gardan "neck;" Mid.Pers. galôg, griv "throat," gartan "neck," Av. grīvā- "neck;" Skt. gala- "throat, neck," Gk. bora "food;" L. vorare "to devour;" PIE base *gwer- "to swallow, devour."

Âbkand, literally "dug by water," from âb "water" (Mid.Pers. âb "water;" O. Pers. ap- "water;" Av. ap- "water;" cf. Skt. áp- "water;" Hitt. happa- "water;" PIE āp-, ab- "water, river;" cf. Gk. Apidanos, proper noun, a river in Thessalia; L. amnis "stream, river" (from *abnis); O.Ir. ab "river," O.Prus. ape "stream," Lith. upé "stream;" Latv. upe "brook") + kand, contraction of kandé, p.p. of kandan "to dig" (Mid.Pers. kandan "to dig;" O.Pers. kan- "to dig," akaniya- "it was dug;" Av. kan- "to dig," uskən- "to dig out" (→ ex- for prefix us-); cf. Skt. khan- "to dig," khanati "he digs").

Gum Nebula
  میغ ِ گام   
miq-e Gâm

Fr.: nébuleuse de Gum   

An immense emission nebula about 40° across lying toward the southern constellations → Vela and → Puppis. It contains the → Vela pulsar and the → Vela supernova remnant, and seems to be created by an outburst of ionizing radiation that accompanied a → supernova explosion.

Named after its discoverer, the Australian astronomer Colin Stanley Gum (1924-1960); → nebula.

Gunn-Peterson effect
  ا ُسکر ِ گان-پیترسون   
oskar-e Gunn-Peterson

Fr.: effet Gunn-Peterson   

The continuum trough observed in the spectra of high redshift quasars (z> 6) at the blue wing of their Lyman-alpha emission line (1216 Å). It is explained by the scattering of the radiation of the quasar by intergalactic neutral hydrogen on the line of sight. Because of the cosmological expansion, the quasar line is redshifted with respect to the continuum trough. The Gunn-Peterson opacity increases rapidly with redshift. It is interpreted as a strong evidence for the reionization of the Universe around z = 6.

After James E. Gunn and Bruce A. Peterson who predicted the effect in 1965; → effect.

GW170817
     
GW170817

Fr.: GW170817   

The first → gravitational wave event detected in association with an → electromagnetic counterpart. On 2017 August (12h 41m 04s UTC) the gravitational event GW170817 was observed by → Laser Interferometer Gravitational-Wave Observatory (LIGO) and the → Virgo interferometer. 1.7 seconds later the Earth-orbiting Fermi and INTEGRAL observatories detected a → gamma-ray burst (GRB 170817A). The gravitational wave data were used to attribute the event to the → merger of → neutron stars in a → neutron star binary system. The component masses range 1.17-1.60 → solar masses (Abbott et al., 2017, Physical Review Letters 119, 161101). The source was rapidly localized to a region of 31 deg2 using data from all three detectors. The analysis of the gravitational wave data suggested a distance of 40 (± 8) Mpc for the event. 45 min after sunset in Chile and 10 hours after the GW trigger, astronomers (Coulter et al. 2017, GCN 21529) located the → electromagnetic counterpart of the gravitational wave event in the → lenticular galaxy (S0) → NGC 4993 offset 10.6 arcseconds north-east from center (corresponding to 2.0 kpc). Follow-up observations revealed an optical-infrared → transient known as → kilonova that lasted a few days, as predicted by models of neutron star merger. Kilonova is powered by the synthesis of large amounts of very heavy elements via rapid neutron capture (the → r-process). The merger ejected 0.03-0.05 → solar masses, including high opacity → lanthanides. Kilonovae are believed to be cradles of production of rare → chemical elements like → gold and → platinum (Pian et al., 2017, Nature doi:10.1038/nature24298).

GW, short for → gravitational wave; 170817 detection date, 2017 August 17.

gyrate
  لِریدن   
leridan

Fr.: tournoyer   

To move in a circle or spiral, or around a fixed point; to revolve in or as if in a spiral course. Close concepts: → revolve; → rotate; → spin. See also: → gyro-.

From L. gyratus, p.p. of gyrare "to turn around," from L. gyrus "circle," from Gk. gyros "circle, ring;" PIE base *geu- "to bend, curve."

Leridan, from Lori, Laki lerr "revolving, whirling, turning" (lerr dâye "to make rotate, to stir a liquid," lerese "to rotate, turn"), variant xer "circular, round" (xer dâyen "to make turn"), maybe cognate with Gk. gyros "circle, ring," as above; variants in Mod.Pers. lulé "rolled-up, wound-up; tube," lulé kardan "to roll up, wind up;" Hamadâni lul "spiral, twisted;" Kurd. lûl "curly (of hair)," garda-lûl, ~ lûlân "wind that whirls dust."

GYRE
     
GYRE

Fr.: GYRE   

An open-source (adiabatic/non-adiabatic) pulsation code that calculates the oscillation frequencies of an input stellar model. The code is based on a "Magnus Multiple Shooting" scheme, which is a numerical technique to solve boundary value problems. This is done by subdividing the possible solution space into sub-intervals and solving the pulsation equation in these sub-intervals, assuming continuity conditions. GYRE is integrated into → Modules for Experiments in Stellar Astrophysics (MESA)'s → asteroseismologic module (Townsend & Teitler, 2013, MNRAS 435, 3406).

GYRE, of unknown origin.

gyro-
  لر-   
ler-

Fr.: gyro-   

A combining form meaning "ring, circle, spiral," used in the formation of compound words: → gyroscope, → gyrofrequency, → gyroradius, → gyrate.

From Gk. gyros "circle, ring;" PIE base *geu- "to bend, curve."

From leridan, → gyrate.

gyrofrequency
  لِربسامد   
lerbasâmad

Fr.: fréquence gyromagnétique   

The frequency with which an electron or other charged particle executes spiral gyrations in moving across a magnetic field.

gyro-; → frequency.

gyroradius
  لرشعاع   
leršo'â'

Fr.: gyrorayon   

Same as → Larmor radius.

gyro-; → radius.

gyroscope
  لِرنما، چرخش‌نما   
lernemâ, carxešnemâ

Fr.: gyroscope   

A device for measuring or maintaining orientation. Consisting of a rotating wheel so mounted that its axis can turn freely in certain or all directions, it is based on the principle of conservation of angular momentum. In physics this is also known as gyroscopic inertia or rigidity in space.

Gyroscope, from gyro-, → gyrate + → -scope.

Lernemâ, from ler, → gyrate, + -nemâ-scope; carxešnemâ, from carxešrotation + -nemâ.

GZK cutoff
  بره‌ی ِ گریسن-زاتسپین-کوزمین   
bore-ye Greisen-Zatsepin-Kuzmin

Fr.: limite de Greisen-Zatsepin-Kuzmin   

Same as → Greisen-Zatsepin-Kuzmin cutoff.

Greisen-Zatsepin-Kuzmin cutoff.

H and K lines
  خطهای ِ H و K   
xatthâ-ye H o K

Fr.: raies H et K   

Two prominent → absorption lines, at 3968.5 Å and 3933.7 Å respectively, in the spectra of stars like the → Sun and cooler due to → singly ionized → calcium (Ca II). The strength of H and K lines can be an indication of considerable magnetic activity in the → chromosphere of these stars. The Ca II H and K lines are also common in some kinds of → eruptive variable stars. These lines are not seen in → hot stars, and start to become visible in → A-type stars.

H and K, letters of alphabet, conventionally chosen; → line.

H I
  H I   
H I

Fr.: H I   

Atomic or → neutral hydrogen.

From H, abbreviation of hydrogen + I "one" in Roman number system, nomenclature convention representing neutral atoms.

H I region
  ناحیه‌ی ِ H I   
nâhiye-ye H I

Fr.: région H I   

A region of neutral (atomic) hydrogen in interstellar space. At least 95 percent of interstellar hydrogen is H I. It emits radio waves that are 21 cm long.

H I; → region

H II
  H II   
H II

Fr.: H II   

Ionized → hydrogen, that is a proton nucleus that has lost its unique electron.

From H, abbreviation of hydrogen + II "two" in Roman number system, nomenclature convention representing singly ionized atoms.

H II galaxy
  کهکشان ِ H II   
kahkešân-e H II

Fr.: galaxie H II   

A low-mass and → metal-poor galaxy (1/30-1/3 Zsun), experiencing strong episodes of → star formation, characterized by the presence of bright → emission lines on a faint → blue continuum. The fact that H II galaxies are metal poor and very blue objects seems to suggest that they are young. Nevertheless, several studies show the existence of an → old stellar population underlying the present → star burst in most of these galaxies. This fact indicates that these objects are not young systems forming their first generation of stars. Same as → blue compact dwarf galaxy.
Spectroscopically, H II galaxies are essentially identical to the → giant H II regions found in nearby → irregular and → late-type galaxies. The correlation among structural parameters (→ H-beta → luminosity, → velocity dispersion, → linewidths) and between these parameters and the → chemical composition favors the interpretation of H II galaxies as giant H II regions in distant → dwarf irregular galaxies similar to the ones found nearby. Some examples of H II galaxies are: I Zw 18, SBS 0335-052, II Zw 33, UM 408.

H II; → galaxy.

H II region
  ناحیه‌ی ِ H II   
nâhiye-ye H II

Fr.: région H II   

A type of → emission nebulae composed of very hot gas (about 104 K), mainly ionized hydrogen, created by the ultraviolet radiation of → massive stars. H II regions originate when O or early-type stars, born in → giant molecular clouds, start heating up the cold gas, causing it to become → ionized and "glow". The effective temperatures of the → exciting stars are in the range 3 x 104 to 5 x 104 K, and throughout the nebula hydrogen is ionized. Helium is → singly ionized, and other elements are mostly singly or → doubly ionized. Typical densities in the H II region are of the order 10 to 102 cm-3, ranging as high as 104 cm-3. Internal motions occur in the gas with velocities of order 10 km s-1. The spectra of H II regions are mainly composed of strong → H Irecombination lines and → forbidden lines such as [O III], [O II], [N II]. See also → ionization-bounded H II region; → density-bounded H II region; → compact H II region; → ultracompact H II region.

H II; → region

H II region luminosity
  تابندگی ِ ناحیه‌ی ِ H II   
tâbandegi-ye nâhiye-ye H II

Fr.: luminosité de région H II   

The total number of → Lyman continuum photons emitted by an → H II region. It is usually derived using → radio continuum observations which are less affected by → interstellar extinction. The measured value is often a lower limit because of photon leakage from the H II region and absorption. See also → density-bounded H II region.

H II; → region; → luminosity.

<< < -es -it -sc 201 951 abe abs abs aca acc acc aco act ada adh ado aer aft air Alf alg alk alp Alt alt amb ana And ang ani ann ant ant ant apo app app Apu arc arg Arn art ass ast ast ast atm ato att aur aut avo azi bac bal bar bar bat Bea Bel bet bia big bin bio Bir bla bla blo Blu bol Boo bou box bre Bri bro bur cal cal Can cap car Car cat cau cel cen cen cha Cha cha che Chi chr cir cir civ cla clo clo CMB coa coe coh col col col com com com com com com com com Com con con con con con con con con con con con con coo cor cor cor Cos cos cos cou cou cra cri cro cry cul cur cyc D l dar dat day dea dec dec dec def def deg Del Den dep der det deu dew dic dif dif dil dip dir dis dis dis dis dis diu dog Dop dou Dra Dsc dus dwa dyn Dys Ear ecc eco edg egg Ein Ela ele ele ele ele ell eme emp enc eng ent epi equ equ equ eru eth Eur eve exa exc exe exi exo exp ext ext ext fab fai Fan fea fem fer fie fil fir fir fla fli flu foc for for for fra fre fre fri fun fuz gal gal gal Gam gau Gau gen geo geo geo geo Gib glo gov gra gra gra gra gre gro Gui H-a hal Ham har Hay hea hei hel Hel her het hie hig hoa hom hor hot Hub Hug hur hyd hyd hyl hyp ice ide ima ima imp imp inc inc ind ine inf inf inf ing inn ins ins int int int int int int int int inv inv ion iro Isl iso iso Jab jet Jov Jup Kar Kep kil Kip Kra Lag Lam Lan Lar las law lea Leg Leo lev lig lim lin lin lin lit loc loc log Lor low lum lun lun Lym Mac mag mag mag mag mag mai Mal map mas mas mat Mau mea mea med Men mer Mes Met met mic mic Mie mil min Mir mix mod mol mom Moo mor mov mul mur n-b nan nat nea neg Ner neu new New NGC noc nom non non nor nor nuc nuc nul nut obj obl obs occ oct off old one ope opp opt opt orb ord org Ori osc oth ove Owl P-s Pal par par par par Pas pat pec pen per per per per per Pha pha pho pho pho phy pie pix Pla pla pla pla Pli Poi pol pol pol pol por pos pos pow pre pre pre pre pri pri pri pro pro pro pro pro pro pro pub pul pyc qua qua qua qua qui rad rad rad rad rad rad rai ran rar Ray rea Rea rec rec red red ref ref reg rel rel rel ren res res res res ret rev Ric rig rin roc roo rot rot rur S5- Sal sat sca sca Sch sci Scu sec sec sed sel sel sem seq set sha she sho sid sie sil sim sin sit sky slo sno sod sol sol sol sol son sou spa spa spe spe spe spe sph spi spo squ sta sta sta sta ste ste ste Sti sto str str sub sub sub sul sup sup sup sup sur sur syl syn sys tal Tay tel ten ter tex the the the the Tho thr tid tim Tit too Tor tra tra Tra tra Tra tri Tri tru tub tur two Typ ult ult unc uni uni uni upl ura uti val var vec vel ver Ver vie vir vis vis vol W-R war wav wav wea Wei wha wid win WN3 Wol wri xen yok zen zij > >>