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 -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
beryllium
  بریلیوم   
beriliom (#)

Fr.: béryllium   

A grey, very hard metallic chemical element; symbol Be. → Atomic number 4; → atomic weight 9.01218; → melting point about 1,278°C; → boiling point 2,970°C (estimated); → specific gravity 1.85 at 20°C; → valence +2. Beryllium occurs as beryl, from which it is obtained by electrolysis. Used for light alloys which are corrosion resistant. Beryllium was discovered by Louis Nicolas Vauquelin (1763-1829) in 1798. First isolated by Friedrich Wöhler (1800-1882) in 1828.

From L. beryll(us), from beryl, a mineral, beryllium aluminum silicate, Be3Al2Si6O18, M.E. beril, from O.Fr., from L. berillus, from Gk. beryllos, + → -ium.

Bessel
  بسل   
Besel

Fr.: Bessel   

From Friedrich Wilhelm Bessel (1784-1846), German astronomer and mathematicians, who made fundamental contributions to positional and spherical astronomy.

Bessel equation
  هموگش ِ بسل   
hamugeš-e Besel

Fr.: équation de Bessel   

A linear second-order differential equation, the solutions to which are called Bessel functions.

From → Bessel; → equation

Hamugeš, → equation.

Bessel's star
  ستاره‌ی ِ بسل   
setâre-ye Bessel

Fr.: étoile de Bessel   

Same as → 61 Cygni, the first star whose distance was measured, by Friedrich Bessel in 1838.

Bessel; → star.

Besselian
  بسلی   
Besseli

Fr.: besselien, de Bessel   

Of or pertaining to Friedrich Wilhelm Bessel (1784-1846) or to his discoveries. → Besselian day number Bessel equation Besselian star constant Besselian year.

Bessel.

Besselian day number
  شماره‌ی ِ روز ِ بسلی   
šomâre-ye ruz-e Besseli

Fr.:   

Any of the five quantities denoted by A, B, C, D, and E used in conjunction with → Besselian star constants for the reduction of a star's → mean catalog place to its → apparent place.

Besselian; → day; → number.

Besselian star constant
  پایای ِ اختری ِ بسلی   
pâyâ-ye axtari-ye Besseli

Fr.: constante stellaire besselienne   

Any of the eight quantities denoted by a, b, c, d (for → right ascension) and a', b', c', d' (for → declination) used in conjunction with → Besselian day numbers for the reduction of star's → mean catalog place.

Besselian; → star; → constant.

Besselian year
  سال ِ بسلی   
sâl-e Beseli

Fr.: année besselienne   

The period taken for the right ascension of the mean Sun to increase by 24 hours. The starting point is when the mean Sun's longitude is 280°, corresponding roughly to January 1. It is virtually the same as the tropical year.

Besselian; → year.

best fit
  بهترین سز   
behtarin saz

Fr.: meilleur ajustement   

In a scatter plot, a mathematical line or curve that passes as near to as many of the data points as possible.

Best, M.E., from O.E. betst, akin toi O.E. bot "remedy." Fit, from M.E. fitten "to marchal troops," from or akin to M.Dutch vitten "to be suitable."

Behtarin supperlative of beh "good, fine" (Mid.Pers. veh "better, good," O.Pers. vahav-, vahu-, Av. vah-, vohu- "good," cf. Skt. vasu- "good," Hittite wasu-, Gaulish vesus "good") + saz, from sazidan "to be fit, proper," from Mid.Pers. saz, sazistan "to be fitting, proper."

Beta Andromedae
  بتا-آندرومدا   
Betâ-Andromedâ

Fr.: Beta Andromedae   

The brightest star in the constellation → Andromeda with an average → apparent visual magnitude of 2.05. It is a red (B - V = +1.57), → giant star of → spectral type M0 III. Beta And lies at a distance of 197 ± 7 → light-years (61 ± 2 → parsecs). It has a mass of 3-4 Msun (→ solar mass), a → luminosity of ~ 2,000 Lsun (→ solar luminosity), and a radius of 100 Rsun (→ solar radius). Its other designations include: Mirach, Merach, Mirac, Mizar, 43 Andromedae, BD+34°198, HD 6860, HIP 5447, HR 337, LTT 10420, and SAO 54471. Beta And happens to lie nearly along the → line of sight to the galaxy → NGC 404. This galaxy, known as → Mirach's Ghost, is visible seven arc-minutes away.

Beta, a Greek letter of alphabet used in the → Bayer designation; → Andromeda

Beta Cephei
  بتا-کفؤس   
betâ-Kefeus

Fr.: bêta Céphée   

The second brightest star in the constellation → Cepheus and the prototype of → Beta Cephei variables. It is a variable B2 type → giant star with a visual magnitude of 3.23 varying with a period of 4.57 hours. Its mass is a dozen times that of the Sun. Beta Cephei is a → triple system lying at a distance of about 600 → light-years. The inner → spectroscopic companion, → spectral type A, is only about 45 AU away, and takes around 90 years to orbit. The third visual companion is at least 2400 AU away, with an orbital period of at least 30,000 years.

Beta (β), the second letter of the Gk. alphabet; → Cepheus.

Beta Cephei variable
  ورتنده‌ی ِ بتا-کفؤسی   
vartande-ye betâ Kefeusi

Fr.: variables bêta Céphée   

A variable star, of early B or late O types, undergoing radial pulsations with short periods (< 1 day). Beta Cephei stars are confined within a narrow band of the → H-R diagram above the upper → main sequence. They are believed to be near the end of core hydrogen-burning stars of approximately 10 to 20 solar masses. The famous bright stars → Spica and → Mirzam belong to this family.

Beta Cephei; → variable.

beta decay
  تباهی ِ بتا   
tabâhi-ye betâ (#)

Fr.: désintegration bêta   

The transformation of a → radioactive nuclide in which a → beta particle is emitted. In beta minus decay, a → neutron changes into a → proton, → antineutrino, and → electron: n → p + e + ν-. Beta plus decay involves the conversion of a proton to a neutron, → positron, and → neutrino: p → n + e+ + ν.

Beta (β), from → beta particle; → decay.

beta minus decay
  تباهی ِ بتا کمن   
tabâhi-ye betâ kaman

Fr.: désintegration bêta moins   

beta particle.

beta particle; → minus; → decay.

beta particle
  ذره‌ی ِ بتا   
zarre-ye betâ (#)

Fr.: particule bêta   

An → electron or a → positron emitted from an unstable nucleus during a → radioactive process known as → beta decay.

The term "beta particle" relates to the early history of the → radioactivity studies when the nature of the emergent particles was not elucidated; → particle.

Beta Pictoris (β Pic)
  بتا-نگارگر   
betâ Negârgar

Fr.: bêta Pictoris   

The second brightest star, with an apparent magnitude of 3.86, in the southern constellation → Pictor. Beta Pic is a young star of spectral type A lying 63 → light-years away. It has a luminosity 8.6 times that of the Sun and its surface temperature is 8250 K. Beta Pic is surrounded by a dust and gas disk stretching 400 A.U. away from the star in each direction, 10 times the average distance of Pluto from the Sun. The disk is not symmetric, one side is brighter than the other. Moreover, it has an inner clear zone about the size of our solar system (some 30 A.U.). Recently a probable giant → exoplanet lying in the disk has been imaged.

Beta (β), the second letter of the Gk. alphabet; → Pictor.

beta plus decay
  تباهی ِ بتا بیشن   
tabâhi-ye betâ bišan

Fr.: désintegration bêta plus   

beta particle.

beta particle; → plus; → decay.

beta-meteoroid
  بتا-شخانه‌وار   
β-šaxânevâr

Fr.: β-météoroïde   

A solid object with a mass about 10-18-10-15 kg in → interplanetary space that moves in hyperbolic orbit as a result of the solar → radiation pressure.

meteoroid.

Betelgeuse (α Orionis)
  ابط‌الجوزا   
Ebtoljowzâ (#)

Fr.: Bételgeuse   

The → red supergiant that is the second brightest star in the constellation → Orion. Betelgeuse is one of the biggest stars known with a size of almost 1,000 times larger than the Sun, corresponding to an angular diameter of 43.76 ± 0.12 milli-arcseconds (Perrin et al. 2004, A&A 418, 675). It is a → semiregular variable whose → apparent visual magnitude varies between 0.2 and 1.2 shining very rarely more brightly than its neighbor → Rigel. The energy released by Betelgeuse is estimated to be only 13% in the form of visible light, with most of its radiation being at → infrared wavelengths. The distance of Betelgeuse is 643±146 → light-years (Harper et al. 2008, AJ 135, 1430), while its luminosity is about 140,000 times that of the Sun (→ solar luminosity). Its → spectral type is M2 Iab, its → surface temperature about 3,600 K, and its → initial mass 10 to 20 → solar masses (Msun). Neilson & Lester (2011, arXiv:1109.4562) recently proposed a mass of 11.6 (+5.0, -3.9) Msun for Betelgeuse, while Dolan et al. (2008, BAPS 53, APR.S8.6) obtained about 21 Msun. Its → rotation period is estimated to be about 17 years (Uittenbroek et al. 1998, AJ 116, 2501). Recent observations with the → Very Large Telescope resolve not only the apparent surface of Betelgeuse, but also reveal a large and previously unknown plume of gas extending into space from the surface of the star (Kervella et al. 2009, A&A 504, 115). The plume extends to at least six times the diameter of the star, corresponding to the distance between the Sun and Neptune. This detection suggests that the whole outer shell of Betelgeuse is not shedding matter evenly in all directions. More recently, an image of the surface of the star was obtained using long → baseline → interferometry at infrared wavelengths (Haubois et al. 2009, A&A 508, 923). It shows the presence of an irregular flux distribution possibly caused by enormous → convective cells. A very large dusty envelope has also been observed at larger distances from the star (Kervella et al. 2011, A&A 531, A117).

Betelgeuse, from Ar. Ibt al-Jauza' (ابط‌الجوزاء) "the armpit of Jauza'," from ibt "armpit" + Jauza' "Orion."

Ebtoljowzâ, from Ar. Ibt al-Jauza'.

bethe
  بته   
bethe

Fr.: bethe   

A unit of energy equal to 1044 → joules or 1051 → ergs, corresponding to the amount of energy liberated in a typical → supernova explosion. It is used by some theoreticians.

In honor of Hans Bethe (1906-2005), Nobel Prize in Physics (1967), for his work on the theory of stellar nucleosynthesis. The unit name was proposed by Steven Weinberg (1933-) in 2006 for Bethe's contributions to the supernova research aftre 1980.

<< < -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 > >>