<< < -es -iv -ti 21 a p abe abs abs aca acc acc acr act ada adh Adr aer AGB air Alf Alg all alp alt AM amo ana And ang ani ano Ant Ant apa apo app app Ara Arc ari Arr ash ass ast ast asy atm ato att aut ave axi Bab bal Bal bar bar bea Bek Bes bia Big bin bin bip biv bla bli blu Boh Bol Bos bou bra bri bro buo cal cal can cap car Car cat cat CCD Cen cen CH cha cha che Che chr cir cir cit cla clo clo clu 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 Cop Cor cor cor cos cos cou cou Cow cre cri cro cry cur cya Cyg dan dar dat de- deb dec dec ded def deg del dem den dep des det dev dia dif dif dih dio Dir dis dis dis dis dis dis DO don dou dow dro dur dwa dyn Dys ear ebb ecl edg egg Ein Ela ele ele ele ele ell eme emp enc eng ent epi equ equ equ esc eth Eur Eve exa exc exe exi exp exp ext ext ext fac fal far fed Fer fer fie fin fir fis fla flo flu fol for for fou fra fre Fre fro fut G-t gal gal gam gas Gau Gem gen geo geo geo gia Gli Gol gra gra gra gra gre gri gui H I Hag hal har hat He- hea hel Hel her Hes hie hig his hom hor hot Hub Hug hur hyd hyd hyg 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 Io ion iro isl iso iso Jac jet jud jur Kel Kep kil Klo Kui Lag lam Lap Lar lat law lea len lep Lib lig lim lin lin Lio lit loc LOF lon Lor low lum lun Lup Lyo mac mag mag mag mag mag mai man Mar mas mas mat Max mea mec Meg Mer Mer met met Met mic Mid Mil min Mir mit mod mod mol mon Mor mou mul mul mys nan Nat nau nec neo neu nev New NGC no nom non non nor not nuc nuc num nut obj obs obs occ ocu oft ome Oor ope opp opt opt orb ord ori ort osc out ove oxi pai pan par par par par pas pea pen per per per per Per per pha phi pho pho pho phy pio Pla pla pla pla Pla plu Poi pol pol pol poo pos pos pot pra pre pre pre pre pri pri pro pro pro pro pro Pro pro pse pul pur qua qua qua qua que rac rad rad rad rad rad rad 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 Rus Sac sal sat sca sca Sch sci Scu sec sec Sed sel Sel sen ser Sex Sha she sho sid sig sil sim sin siz sla Sma sno sof sol sol sol sol sou sou spa spa spe spe spe sph spi spi spr squ sta sta sta sta ste ste ste Sto Str str str sub sub suc sun sup sup sup sup sur swa syn syn tab tar tek tem ter tes the the the the Tho thr tid tim Tis Too Tor tra tra Tra tra tra tri tri tru Tul tur two Typ ult un- und uni uni unk upp Urc utt val var vec vel ver vib vio vir vis voi vor wan wat wav wax wea Wei whi Wil win WN9 wor X-r yel you zer zod > >>
beam of light tâbe-ye nur (#) Fr.: faisceau lumineux A relatively large bundle of → rays of light. See also → pencil of light. |
beam of particles tâbe-ye zarré Fr.: faisceau de particules A narrow unidirectional flow of particles |
beam splitter fâqgar-e tâbé Fr.: lame séparatrice A partially reflecting mirror which permits a part of the light beam to pass through and reflects the rest. → beam; splitter, from to split, from M.Du. splitten, from P.Gmc. *spl(e)it-, PIE *(s)plei- "to split, splice." Fâqgar, from fâq "split, breach, division" + tâbé→ beam. |
beam switching degarbâni-ye tâbé Fr.: permutation de lobe In single dish radio astronomy, any technique which forms the difference of signals received from two (or more) pointings on the sky without physically moving the main reflector of the antenna. By rapidly forming differences between sky positions that do and do not contain astronomical sources, beam switching can minimize the corruption of spectral baselines by non-idealities in the instrumental frequency response, or of continuum observations by atmospheric fluctuations. |
beamwidth tâbe-pahnâ Fr.: largeur de lobe The angle between the two directions in the main beam at which the power response has fallen to half its maximum value. → beam efficiency. |
beat zaneš (#) Fr.: battement The periodic and alternatively strengthening and weakening of two waves of similar frequencies when they interfere with one another. In particular, the soft and loud sounds created by the interference of two sound waves of similar frequencies. M.E. beten, from O.E. beaten, from P.Gmc. *bautan; IER *bhau- "to strike." Zaneš, noun from zan- present tense stem of zadan "to beat, strike" + -š verbal noun suffix. Zadan from Mid.Pers. zatan, žatan; O.Pers./Av. jan-, gan- "to strike, hit, smite, kill" (jantar- "smiter"); cf. Skt. han- "to strike, beat" (hantar- "smiter, killer"); Gk. theinein "to strike;" L. fendere "to strike, push;" Gmc. *gundjo "war, battle;" PIE *gwhen- "to strike, kill." |
beat Cepheid kefeusi-ye zaneši Fr.: céphéide à battement A Cepheid variable in which two or more almost identical periods of variability pass into and out of phase with each other, producing periodic amplitude fluctuations in their light curves. Beat periods are typically about 2 hours. |
beat frequency basâmad-e zaneš Fr.: fréquence de battement One of the frequencies that results from the combination of two waves of slightly different frquencies. A beat frequency is equal to the absolute value of the difference between the two frequencies. An unknown frequency can be determined by beating it with a reference frequency. More specifically, when the two frequencies are superimposed, the phase difference will change with time and wave interference alternate between constructive and destructive. The alterations of intensity brings about a beat frequency. |
Beaufort scale marpel-e Beaufort Fr.: échelle de Beaufort A system for estimating and reporting wind speeds which has 13 standardized categories and associated descriptions. The Beaufort scale ranges from 0 for complete calm to 12 for a cyclone. In this scale, the wind speed (in km/h) equals 3B1.5, where B is the Beaufort number of the wind. The scale was originally devised for use at sea but has subsequently been modified for use over land. Named after Admiral Sir Francis Beaufort (1774-1857), who introduced the first version of the system in 1805; → scale. |
beauty zibâyi (#) Fr.: beauté A combination of qualities that pleases the mind. M.E. be(a)ute, from O.Fr. beautez, beltet "beauty, seductiveness, beautiful person" from V.L. bellitatem (nominative bellitas) "state of being handsome," from L. bellus "pretty, charming." Zibâyi, from zibâ "beautiful," related to zib "beauty, elegance, ornament," zibidan "to suit, to adorn." |
beaver bidastar (#) Fr.: castor A large, amphibious rodent of the genus Castor, having sharp incisors, webbed hind feet, and a flattened tail, noted for its ability to dam streams with trees, branches, etc. (Dictionary.com). M.E. bever, O.E. beofor, befor; cognate with Ger. Biber; Av. bawra-, bawri- "beaver" (Mid.Pers. bawrak "beaver"); Skt. babhrav- "reddish-brown," babhrus- "mangoose," L. fiber "beaver" (Fr. bièvre "River of Beavers"); O.H.G. biorr; Lith. bêbrus; Rus. bobr "beaver." Bidastar "beaver," of unknown origin. |
because zirâ (#) Fr.: parce que For the reason that; on account of. M.E. bi cause "by cause," from O.E. bi "by" (akin to Du. bij, O.H.G. bi, Ger. bei, Goth. bi) + → cause. Zirâ, variants azirâ, zirâk, azirâk, from Mid.Pers. êt rây cê or ê(t) râd cê "because," literally "this reason why;" from êd "this" (O.Pers. aita; Av. aēta "this;" cf. Skt. etá); rây, → reason; cê "what" (O.Pers/Av. ci- "what, any," collateral stem to ka- "who?, what?;" cf. Skt. ka-; Gk. po-; L. quo-; E. what, who; PIE *qwos/*qwes). |
Becklin-Neugebauer object barâxt-e Becklin-Neugebauer Fr.: objet de Becklin-Neugebauer A compact infrared source in the Orion molecular cloud (OMC-1). It is thought to be a very dusty compact H II region surrounding a young B0 or B1 star. After Eric Becklin (1940-), and Gerry Neugebauer (1932-) who discovered the object in 1967; → object. |
become šodan (#) Fr.: devenir To come, change, or grow to be. M.E. becumen; O.E. becuman "happen, come about," also "meet with, arrive;" akin to Du. bekomen, O.H.G. biqueman "obtain," Ger. bekommen, Goth. biquiman; from be- a prefix denoting several meanings, and → come. Šodan "to become, to go, to pass, to change," from Mid.Pers. šudan, šaw- "to go;" Av. š(ii)auu-, šiyav- "to move, go," šiyavati "goes," šyaoθna- "activity; action; doing, working;" O.Pers. šiyav- "to go forth, set," ašiyavam "I set forth;" cf. Skt. cyu- "to move to and fro, shake about; to stir," cyávate "stirs himself, goes;" Gk. kinein "to move;" Goth. haitan "call, be called;" O.E. hatan "command, call;" PIE base *kei- "to move to and fro." |
becquerel becquerel (#) Fr.: becquerel The → SI unit of → radioactivity. One becquerel corresponds to the → disintegration of one atom per second. Abbreviation: Bq. → curie. Named for the French physicist Henri Becquerel (1852-1908), who discovered radioactivity in 1896. |
Bedin I Bedin I Fr.: Bedin I A → dwarf spheroidal galaxy belonging to the → Local Group that was discovered serendipitously in 2019. Bedin I was detected using extremely deep → HST images (V ~ 30 mag) obtained for the purpose of investigating the → white dwarf cooling track of the Galactic → globular cluster NGC 6752. Bedin I is too faint and too close to the core of NGC 6752 for detection in earlier surveys. The discovery paper derives a → distance modulus of (m - M)0 = 29.70 ± 0.13 mag from the observed → red giant branch, i.e. ~ 8.7 → megaparsecs (~ 30 million → light-years), and a size of ~ 840 × 340 pc, about one-fifth the size of the → Large Magellanic Cloud. This object is most likely a relatively isolated → satellite galaxy of the nearby great → spiral galaxy NGC 6744. The study suggests the presence of an old (~ 13 Gyr) and → metal-poor ([Fe/H] ~ -1.3) population in Bedin I. Named after the first author of the discovery paper, L. R. Bedin et al., 2019, MNRAS 484, L54. |
bedrock sangbastar (#) Fr.: socle Solid → rock present beneath any → soil, → sediment, or other surface cover. In some locations it may be exposed at earth's surface. Bedrock, from bed (O.E. bed, from P.Gmc. *badjam "sleeping place dug in the ground;" PIE *bhedh- "to dig, pierce") + → rock. Sangbastar, from sang "stone, rock," → stone, + bastar "bed" (Mid.Pers. vistarak, cognate with Mod.Pers. gostar "a bed; spreading; scatterer," Av. star-, starəta- "spread," from star- "to spread," Skt. strnâti). |
beech râš (#) Fr.: hêtre Any tree of the genus Fagus, especially Fagus sylvatica of Europe, having smooth grayish bark. In Iran Fagus orientalis populates Caspian highland forests from Âstârâ to Gorgân. M.E. beche, from O.E. becew; cf. Dutch beuk, Ger. Buche, from PIE root *bhagos "beech tree;" also cf. Gk. phegos "oak," L. fagus "beech," Rus. buzina "elder." Râš, as named in Gilân, Râmsar, Šahsavâr, Kalârdašt. Its other names: (Mâzandarân) mers, (Ammaârlu, Manjil) râj, (Tevâleš, Mt. Dorfak) aluš, alâš, âlâš, (Nur) celer, celar (Iranica). |
Beehive Cluster xuše-ye kandu Fr.: amas de la ruche → Praesepe. |
behavior raftâr (#) Fr.: comportement Manner of behaving or acting. M.E. behavour, from behaven "to behave," altered by model havour, from O.Fr. avoir "to have." Raftâr "behavior, walking, going," from raft past tense stem of raftan "to go, walk, proceed" (present tense stem row-, Mid.Pers. raftan, raw-, Proto-Iranian *rab/f- "to go; to attack") + -âr prefix forming action noun. |
<< < -es -iv -ti 21 a p abe abs abs aca acc acc acr act ada adh Adr aer AGB air Alf Alg all alp alt AM amo ana And ang ani ano Ant Ant apa apo app app Ara Arc ari Arr ash ass ast ast asy atm ato att aut ave axi Bab bal Bal bar bar bea Bek Bes bia Big bin bin bip biv bla bli blu Boh Bol Bos bou bra bri bro buo cal cal can cap car Car cat cat CCD Cen cen CH cha cha che Che chr cir cir cit cla clo clo clu 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 Cop Cor cor cor cos cos cou cou Cow cre cri cro cry cur cya Cyg dan dar dat de- deb dec dec ded def deg del dem den dep des det dev dia dif dif dih dio Dir dis dis dis dis dis dis DO don dou dow dro dur dwa dyn Dys ear ebb ecl edg egg Ein Ela ele ele ele ele ell eme emp enc eng ent epi equ equ equ esc eth Eur Eve exa exc exe exi exp exp ext ext ext fac fal far fed Fer fer fie fin fir fis fla flo flu fol for for fou fra fre Fre fro fut G-t gal gal gam gas Gau Gem gen geo geo geo gia Gli Gol gra gra gra gra gre gri gui H I Hag hal har hat He- hea hel Hel her Hes hie hig his hom hor hot Hub Hug hur hyd hyd hyg 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 Io ion iro isl iso iso Jac jet jud jur Kel Kep kil Klo Kui Lag lam Lap Lar lat law lea len lep Lib lig lim lin lin Lio lit loc LOF lon Lor low lum lun Lup Lyo mac mag mag mag mag mag mai man Mar mas mas mat Max mea mec Meg Mer Mer met met Met mic Mid Mil min Mir mit mod mod mol mon Mor mou mul mul mys nan Nat nau nec neo neu nev New NGC no nom non non nor not nuc nuc num nut obj obs obs occ ocu oft ome Oor ope opp opt opt orb ord ori ort osc out ove oxi pai pan par par par par pas pea pen per per per per Per per pha phi pho pho pho phy pio Pla pla pla pla Pla plu Poi pol pol pol poo pos pos pot pra pre pre pre pre pri pri pro pro pro pro pro Pro pro pse pul pur qua qua qua qua que rac rad rad rad rad rad rad 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 Rus Sac sal sat sca sca Sch sci Scu sec sec Sed sel Sel sen ser Sex Sha she sho sid sig sil sim sin siz sla Sma sno sof sol sol sol sol sou sou spa spa spe spe spe sph spi spi spr squ sta sta sta sta ste ste ste Sto Str str str sub sub suc sun sup sup sup sup sur swa syn syn tab tar tek tem ter tes the the the the Tho thr tid tim Tis Too Tor tra tra Tra tra tra tri tri tru Tul tur two Typ ult un- und uni uni unk upp Urc utt val var vec vel ver vib vio vir vis voi vor wan wat wav wax wea Wei whi Wil win WN9 wor X-r yel you zer zod > >>