An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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<< < -es -iv -ti 21 a p abe abs abs aca acc acc acr act ada adh Adr aer aga air Alf Alg alk Alp alt alu amm ana And ang ani ano ant ant Ap apo app app Aqu Arc arg arr asc ass ast ast asy atm ato att aur aut axi B-m bad Bal bar bar Bay Bed ber Bet bif bim bin bio bis bla ble blu Bod Bol bor bou Bra Bre bro bul C-t Cal Cam can car Car Cas cat cav cel cen cer Cha cha Cha che chl Cir cir cir Cla cli clo clu co- coc 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 Cre cri cro cub cur cyc cyl Dan dat Dav de- Deb dec dec dee def deg del Den den der det deu dew dic dif dif dil Dip dir dis dis dis dis dis diu dod Dop dou Dra dua dus dwa dyn DZ Ear ecc eco edi EHB Ein ela ele ele ele ele ell eme emp end Eng ent epi equ equ era ESP eth Eur evi exa exc exe exi exp exp ext ext ext fac fal far fec Fer fer fie fin fir fis fla Flo flu fog for for Fou fra fre fre Fro fun G s Gal gal gal Gar gau geg gen geo geo geo ger gla gly gra gra gra gra gra Gre gro GYR Had Hal hap Har HD hea hel hel Hen Her hex hig Hil hol Hoo hor hou Hub hum hyb hyd hyd hyp hys ide ign ima imp imp in- inc Ind ind ine inf inf inf ini ins ins ins int int int int Int int int int inv ion iri irr iso iso iso Jea Jor jum K c Kep Ker kin kno lab Lam Lan Lap las lat Le lef len lev lig lig lin lin lin liq Lit loc log lon lou LS lun lun Lym M s Mag mag mag mag mag mag maj man Mar mas mas mat May mea mec mel mer mes met met met mic mid mil Min Mir mix mod mod mol mon mor mov mul mur mys nan nat nav nec Nep neu New New NGC nob nom non non nor nos nuc nuc num nut obj obl obs occ oct off oli oni ope opp opt opt orb ord org orp osc out ove oxi P-w pal par par par par Pas pat pej per per per per per per pha Phe pho pho pho phy pin pla Pla pla pla pla plu poi pol pol Pol pol por pos pot Poy pre pre pre pre pri pri pri pro pro pro pro pro pro Psa pul pum Q i qua qua qua qua R A rad rad rad rad rad rad Ram Ran rat rea rea rec rec red red ref ref reg rei rel rel rem rep res res res ret rev Rho Rie ril riv rog Ros rot rul S A Sag sam sat sca sca Sch Sco Sec sec sec seg sel sem sen set Sha sha shi sho sid sig sim sin Sir ske sli Smo soc sof sol sol sol sol sou sou spa spe spe Spe spe sph spi Spi spr sta sta sta sta sta ste ste ste Sto str str sub sub sub suc sun sup sup sup sup sur swa syn syn tac tas tel tem ter tes the the the the thi thr tid til tip ton tor tou tra tra tra tra Tri tri tru tsu tur two Typ UHE ult unc uni uni uni upg 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: 13116 Search : far
S Andromedae
   S آندرومدا   
S Andromedâ

Fr.: S Andromedae   

The only supernova seen to date in the Andromeda galaxy and the first supernova observed beyond our own Galaxy. It was recorded on Aug. 20, 1885, by Ernst Hartwig (1851-1923) at Dorpat Observatory (Tartu) in Estonia and independently by other astronomers. S Andromedae reached magnitude 6 between Aug. 17 and 20, and had faded to magnitude 16 by February 1890. It is now believed that S Andromedae was a Type Ia supernova. Also known as SN 1885A.

S, from the second variable star to be discovered in constellation → Andromeda

S asteroid
  سیارک ِ S   
sayyârak-e S

Fr.: astéroïde S   

A moderately bright type of asteroids (albedo 0.10 to 0.22) consisting mainly of iron- and magnesium-silicates such as olivine and pyroxene. They are dominant in the inner main belt within 2.2 AU, common in the central belt within about 3 AU, but become rare further out. The largest is 15 Eunomia (about 330 km in its largest dimension).

S stands for silicaceous, → silicate; → asteroid.

S cluster
  خوشه‌ی ِ S   
xuše-ye S

Fr.: amas S   

A → star cluster situated within an arcsecond, or 0.04 pc, from the → Galactic Center, in the vicinity of the → supermassive black hole Sgr A*. The cluster members are about 40 → main sequence → B-type stars with relatively high orbital → eccentricities (0.3 ≤ e&le 0.95). The most famous member of the S cluster is S2 because of its brightness and its fast orbital motion near Sgr A*. Same as Same as the Sgr A* cluster and S stars. See also other → Galactic center clusters (Figer et al. 2002, ApJ 581, 258; and 1999, ApJ 525, 750).

S, because of proximity to → Sgr A*; → cluster.

S Doradus star
  ستاره‌ی S ِ زرین ماهی   
setâre-ye S Zarrin-mâhi

Fr.: étoiles S Doradus   

A type of massive, → blue supergiant, → variable star, also known as a → Hubble-Sandage variable or a → Luminous Blue Variable (LBV). S Doradus stars are the most luminous stars in the Galaxy and are easily identified in other nearby galaxies. They are named after the prototype, S Doradus, in the → Large Magellanic Cloud.

Dorado; → star.

S star
  ستاره‌ی ِ S   
setâre-ye S

Fr.: étoile de type S   

A → red giant of → spectral type S whose spectrum is dominated by → molecular bands arising from → zirconium → oxide (ZrO). S stars also have strong → cyanogen bands and contain spectral lines of → lithium and → technetium. Almost all S stars are → long-period variables.

S, letter of alphabet; → star.

s-process
  فراروند ِ s   
farâravand-e s

Fr.: processus s   

A → nucleosynthesis process by which → chemical elements heavier than → copper are formed through a slow flux of → neutrons absorbed by atomic nuclei (→ neutron-capture element). The → capture of neutrons occurs on time scales that are long enough to enable unstable nuclei to decay via the emission of a → beta particle before absorbing another neutron. Prominent s-process elements include → barium, → zirconium, and → yttrium. See also: → r-process.

s stands for → slow; → process.

S-type asteroid
  سیارک ِ گونه‌ی ِ S   
sayârak-e gune-ye S

Fr.: astéroïde de type S   

A type of → asteroid containing → pyroxene and → olivine silicates, probably mixed with metallic iron, similar to → stony meteorites. S-type asteroids show high albedo of 0.10-0.22. They include about 17% of known asteroids and occupy the inner → asteroid belt.

S for → stone; → type; → asteroid.

S-type star
  ستاره‌ی ِ گونه‌ی ِ S   
setâre-ye gune-ye S

Fr.: étoile de type S   

Same as → S star.

S, letter of alphabet; → type; → star.

S-wave
  موج ِ S   
mowj-e S

Fr.: onde S   

shear wave.

S, referring to → shear; → wave.

S5-HVS1
   S5-HVS1   
S5-HVS1

Fr.: S5-HVS1   

The fastest → main sequence  → hypervelocity star (HVS) with a → heliocentric  → radial velocity of 1017 ±2.7 km s-1. The star S5-HVS1 is an → A-type with a → luminosity of ~ 2.35 Msun located at a distance of ~ 9 kpc from the Sun. The current 3D velocity of the star in the Galactic frame is 1755 ± 50 km s-1. When integrated backwards in time, the orbit of the star points unambiguously to the → Galactic Center, implying that S5-HVS1 was kicked away from → Sgr A* with a velocity of ~ 1800 km s-1 and travelled for 4.8 Myr to its current location. This is so far the only HVS confidently associated with the Galactic Center. The ejection trajectory and transit time of S5-HVS1 coincide with the orbital plane and age of the annular disk of young stars at the Galactic Centre, and thus may be linked to its formation. With the S5-HVS1 ejection velocity being almost twice the velocity of other hypervelocity stars previously associated with the Galactic Center, the question arises whether they have been generated by the same mechanism or whether the ejection velocity distribution has been constant over time (Koposov, S.E., et al., 2019, arXiv:1907.11725).

S5, or S5, short for Southern Stellar Stream Spectroscopic Survey; HVS, → hypervelocity star (HVS).

Sachs-Wolfe effect
  اُسکر ِ زاخس-وُلف   
oskar-e Sachs-Wolfe

Fr.: effet de Sachs-Wolfe   

The effect of → gravitational potentials on the → anisotropy of the → cosmic microwave background radiation, in which photons from the → CMB are gravitationally → redshifted, causing the CMB spectrum to appear uneven. This effect is the predominant source of fluctuations in the CMB for angular scales above about 10 degrees. It involves two parts: the effect of the potential at the → surface of last scattering, which is the ordinary Sachs-Wolfe effect. And the integrated Sachs-Wolfe (ISW) effec, which is caused by the time variation of gravitational potentials as the photons travel through them. A photon traveling through a decaying → potential well (wall) gains (loses) energy. Without → dark energy the photon is → blueshifted and then → redshifted, so that both effects compensate each other. On the other hand, in an → accelerating Universe driven by dark energy the photon gets more blueshifted. See also → Rees-Sciama effect.

Rainer Kurt Sachs (1932- ) & Arthur Michael Wolfe (1939- ), 1967, ApJ 147, 73; → effect.

Sachs-Wolfe plateau
  تختال ِ زاخس-وُلف   
taxtâl-e Sachs-Wolfe

Fr.: plateau de Sachs-Wolfe   

An almost horizontal region in the → CMB angular power spectrum belonging to a → multipole index 10 ≤ l ≤ 100. This feature is due to the → Sachs-Wolfe effect.

Sachs-Wolfe effect; → plateau.

Sadalmelik (α Aquarii)
  سعد الملک   
sa'delmalek (#)

Fr.: Sadalmelik   

A supergiant star of type G2 Ib situated in the constellation → Aquarius. At a distance of 750 light-years, it has a luminosity 3000 times that of the Sun, and a diameter about 60 times the solar diameter. Variant designations: Sadalmelek; Sadlamulk; El Melik; Saad el Melik.

From Ar. Sa'd al-Malik (سعد الملک) "the lucky star of the ruler," for unknown reasons.

Sadr (γ Cygni)
  صدر   
Sadr (#)

Fr.: Sadr   

The star that lies at the center of → Cygnus's → Northern Cross. This F8 → supergiant is situated some 1,500 → light-years away and has an → apparent visual magnitude of 2.20.

From Ar. as-sadr (الصدر) "breast" (of the Cygnus).

Sagitta
  پیکان   
Peykân (#)

Fr.: Flèche   

The Arrow. A very small → constellation, in fact the third smallest constellation in the sky, lying south of → Vulpecula, and north of → Aquila. The constellation contains the prototype → WZ Sagittae star and M71 (NGC 6838), formerly thought to be an → open cluster but now considered to be a → globular cluster of low condensation. Its brightest star α Sge is a yellow bright → giant of → apparent magnitude +4.37 and → spectral type G1 II about 475 → light-years from Earth. Abbreviation: Sge; Genitive: Sagittae.

From L. sagitta "arrow."

Peykân, → arrow.

Sagittarius
  نیم‌اسب   
Nimasb (#)

Fr.: Sagittaire   

The Archer. A large constellation belonging to the → Zodiac, situated between → Scorpius and → Capricorn. It is located in the southern hemisphere at approximately 19h right ascension, 25° south declination. The constellation, part of which lies in the → Milky Way, contains the → Trifid Nebula, → Lagoon nebula, star clusters, and globular clusters. The center of the Galaxy lies in the direction of Sagittarius. Abbreviation: Sgr; Genitive: Sagittarii.

From L. sagittarius "archer," literally "pertaining to arrows," from → sagitta "arrow" + -arius "-ary." In Gk. mythology, Sagittarius is identified as a centaur, half human, half horse. In some legends, the Centaur Chiron was the son of Philyra and Saturn, who was said to have changed himself into a horse to escape his jealous wife, Rhea. Chiron was eventually immortalized in the constellation of → Centaurus, or in some version, Sagittarius.

Nimasb, from Mid.Pers. nêmasp "centaur, Sagittarius," from nêm, nêmag "mid-, half" (Mod.Pers. nim); Av. naēma- "half;" cf. Skt. néma- "half" + asp "horse" (Mod.Pers. asb); O.Pers. asa- "horse;" Av. aspa- "horse," aspā- "mare," aspaiia- "pertaining to the horse;" cf. Skt. áśva- "horse, steed;" Gk. hippos; L. equus; O.Ir. ech; Goth. aihwa-; O.E. eoh "horse;" PIE base *ekwo- "horse."

Sagittarius A (Sgr A)
  نیم‌اسب A   
Nimasb A

Fr.: Sagittarius A   

A strong radio source at the center of our Galaxy. It is a complex object with three components: Sgr A West is a thermal radio source made of several dust and gas clouds, which orbit → Sgr A* and fall onto it at velocities as high as 1000 km per second. Sgr A East is a → non-thermal source, about 25 → light-years across, that appears to be a → supernova remnant. Sgr A* is the most plausible candidate for the location of a Galactic → supermassive black hole with a mass of about 4 million → solar masses.

Sagittarius.

Sagittarius arm
  بازوی ِ نیم‌اسب   
bâzu-ye Nimasb

Fr.: bras du Sagittaire   

One of the → spiral arms of the Milky Way Galaxy. It lies between the Sun and the the → Scutum-Crux arm. Also known as the Sagittarius-Carina Arm.

Sagittarius; → arm.

Sagittarius B2
  نیم‌اسب B2   
Nimasb B2

Fr.: Sagittarius B2   

A massive (3 × 106 → solar masses), dense (up to 108 particles per cm3) → H II region and → molecular cloud complex located near the → Galactic center (about 390 → light-years from it) and about 26,000 light-years from Earth. This complex is one of the largest in the → Milky Way, spanning a region about 150 light-years across. The mean → hydrogen  → density within the cloud is 3,000 atoms per cm3, which is about 20-40 times denser than a typical molecular cloud. It is the richest molecular source in the Galaxy in which many different types of → interstellar molecule have been identified, including glycine, the simplest amino acid, and the sugar molecule glycoaldehyde.

Sagittarius.

Sagittarius Dwarf Elliptical Galaxy
  کهکشان ِ کوتوله‌ی ِ بیضی‌گون ِ نیم‌اسب   
kahkešân-e kutule-ye beyzigun-e nimasb

Fr.: galaxie naine elliptique du Sagittaire   

A satellite galaxy of the Milky Way discovered only in 1994 since most of it is obscured by the Galactic disc. At only 50,000 light years distant from our Galaxy's core, it is travelling in a polar orbit around the Galaxy. Our Galaxy is slowly devouring it, as evidenced by a filament which stretches around the Milky Way's core like a gossamer loop. It is only about 10,000 light-years in diameter, in comparison to the Milky Way's diameter of 100,000 light years. It is populated by old yellowish stars has four known globular clusters: M54, Arp 2, Terzan 7, and Terzan 8. It should not be confused with the → Sagittarius Dwarf Irregular Galaxy.

Sagittarius; → dwarf; → elliptical; → galaxy.

<< < -es -iv -ti 21 a p abe abs abs aca acc acc acr act ada adh Adr aer aga air Alf Alg alk Alp alt alu amm ana And ang ani ano ant ant Ap apo app app Aqu Arc arg arr asc ass ast ast asy atm ato att aur aut axi B-m bad Bal bar bar Bay Bed ber Bet bif bim bin bio bis bla ble blu Bod Bol bor bou Bra Bre bro bul C-t Cal Cam can car Car Cas cat cav cel cen cer Cha cha Cha che chl Cir cir cir Cla cli clo clu co- coc 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 Cre cri cro cub cur cyc cyl Dan dat Dav de- Deb dec dec dee def deg del Den den der det deu dew dic dif dif dil Dip dir dis dis dis dis dis diu dod Dop dou Dra dua dus dwa dyn DZ Ear ecc eco edi EHB Ein ela ele ele ele ele ell eme emp end Eng ent epi equ equ era ESP eth Eur evi exa exc exe exi exp exp ext ext ext fac fal far fec Fer fer fie fin fir fis fla Flo flu fog for for Fou fra fre fre Fro fun G s Gal gal gal Gar gau geg gen geo geo geo ger gla gly gra gra gra gra gra Gre gro GYR Had Hal hap Har HD hea hel hel Hen Her hex hig Hil hol Hoo hor hou Hub hum hyb hyd hyd hyp hys ide ign ima imp imp in- inc Ind ind ine inf inf inf ini ins ins ins int int int int Int int int int inv ion iri irr iso iso iso Jea Jor jum K c Kep Ker kin kno lab Lam Lan Lap las lat Le lef len lev lig lig lin lin lin liq Lit loc log lon lou LS lun lun Lym M s Mag mag mag mag mag mag maj man Mar mas mas mat May mea mec mel mer mes met met met mic mid mil Min Mir mix mod mod mol mon mor mov mul mur mys nan nat nav nec Nep neu New New NGC nob nom non non nor nos nuc nuc num nut obj obl obs occ oct off oli oni ope opp opt opt orb ord org orp osc out ove oxi P-w pal par par par par Pas pat pej per per per per per per pha Phe pho pho pho phy pin pla Pla pla pla pla plu poi pol pol Pol pol por pos pot Poy pre pre pre pre pri pri pri pro pro pro pro pro pro Psa pul pum Q i qua qua qua qua R A rad rad rad rad rad rad Ram Ran rat rea rea rec rec red red ref ref reg rei rel rel rem rep res res res ret rev Rho Rie ril riv rog Ros rot rul S A Sag sam sat sca sca Sch Sco Sec sec sec seg sel sem sen set Sha sha shi sho sid sig sim sin Sir ske sli Smo soc sof sol sol sol sol sou sou spa spe spe Spe spe sph spi Spi spr sta sta sta sta sta ste ste ste Sto str str sub sub sub suc sun sup sup sup sup sur swa syn syn tac tas tel tem ter tes the the the the thi thr tid til tip ton tor tou tra tra tra tra Tri tri tru tsu tur two Typ UHE ult unc uni uni uni upg 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 > >>