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 r abe abs abs acc acc acc act act ada adi adu aff age alc Alf ali all alp alt ama amp ana ang ang ann ano ant ant ape apo app aps arc Arg ari art ass ast ast ast atm ato att aur aut axi B r bac Bal Bar Bar Bay bec Ber Bet Bie bij bin bio bis bla bla blu blu bol Bor bou Bra bre bro Bug C-s cal Cam can car Car Cas cat cav cel cen cer Cha cha cha che cho cir cir cir 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 coo cor Cor cor cos cos cos Cou cou cra cre cro cru cub cur cyc Cyn dar dat day de- dec dec dec def def deg del den dep Des det deu dex die dif dif dil dip dir dis dis dis dis dis div dom Dor dou Dra duc dus dwa dyn e-t ear ecl eco eff Ein Ein ele ele ele ele ele elv emi emp ene enr epa epo equ equ Err Eta Eul eva evo exc exc exh exo exp exp ext ext Fab fai fan fau fel fer fic fil fin fir fla fli flu foc for for for fra fre fre fro fun fuz 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 hep Her hex hig Him hol hor hos hov Hub Hun hyd hyd hyd hyp IC ide ill Ima imp imp inc inc ind ine inf inf inf ini inp ins ins int int int int Int int int int inv ion Iri irr iso iso ite jel Jou JUp Kan Kep Kil kin 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 mar mas mas mat max mea mec meg men mer met met Met mic mid Mil min Mir mix mod mod mol mon mor mov mul mur n-b nan nat nea neg Ner neu new New NGC noc nom non non nor nou nuc nuc num O-p obl obs obs oce Of? ohm omn opa Oph opt opt or orb ord Ori ort osc out ove ozo pal pan par par par par pat pec pen per per per per per Pfu pha pho pho pho phy pie pla Pla pla pla pla plu poi pol pol pol pol por pos pot pow pre pre pre pre pri pri pri pro pro pro pro Pro pro Prz pul pum Pyx 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 rhy rif Rin rob Rom rot rot rum S s Sak San sav sca Sch Sch scr sec sec SED sei sel sem seq sex Sha she sho sid sig sil sim sin siz sla Sma SNR Sof sol sol sol sol sou sou spa spe spe spe spe sph spi spo squ sta sta sta sta ste ste ste sto sto str str sub sub sub sum sup sup sup sup sur sus sym syn syz tan tea tem ten ter the the the the thi thr tid til tip tom tor tou tra tra tra tra Tri tri tru tsu tur two Typ ult umb unc uni uni unk upp urg uvb val var Veg vel ver vib vio vir vis Voi vow wan wat wav WC wea wel whi Wil wir WNh wor X-r Yer Z s zer [C > >>

Number of Results: 12942 Search : far
HD 43317
     
HD 43317

Fr.: HD 43317   

A → hot star of → apparent visual magnitude 6.61 lying in the constellation → Orion. HD 43317 has a B3.5V → spectral type and has no detected binary companion. Its chemical surface abundances agree with the solar abundances, but with some co-rotating He abundance spots at the stellar surface. The CoRoT satellite revealed that HD 43317 is a → hybrid pulsator of → Slowly Pulsating B star (SPB)/ → Beta Cephei type. Its → rotation period is 0.897673(4) days. Zeeman signatures in the Stokes V profiles of HD 43317 are clearly detected and rotationally modulated, which proves that this star exhibits an oblique magnetic field. The strength of the dipolar magnetic field is of the order of 1 kG to 1.5 kG (Buysschaert et al., 2017, A&A 605, A104).

HD number.

HD 5980
     
HD 5980

Fr.: HD 5980   

A remarkable → binary star system composed of → massive stars that is associated with NGC 346, the largest → H II region + OB star cluster in the → Small Magellanic Cloud. HD 5980 is a rather complex system because it consists of at least three stars: two stars form an → eclipsing binary with a period of 19.266 days, while the third component, an → O star, is detected by means of a set of absorption lines. Whether or not the third star is physically bound to the eclipsing binary remains currently unclear. HD 5980 underwent an → LBV-type event in August 1994. Before the LBV eruption, both components of the eclipsing binary already showed emission lines in their spectra and were thus classified as → Wolf-Rayet stars. However, as shown by the analysis of the spectra taken during and after the LBV event, at least the star that underwent the eruption was not a classical, helium-burning, Wolf-Rayet object, but rather a WNha star. This means a rather massive star with substantial amounts of hydrogen present in its outer layers. These WNha stars have → stellar wind properties that are intermediate between those of extreme → Of stars and classical → WN Wolf-Rayet stars.

Henry Draper system; → number.

HD 93129
     
HD 93129

Fr.: HD 93129   

A multiple → O-type star in the → Trumpler 14 cluster, which consists of at least three components. The main component, HD 93129A, is of spectral type O2 If*, a very rare hot star and the closest known O2 star (Walborn et al. 2002). It is one of the most luminous stars known. HD 93129B, lying 2.7 arcsec apart, is an O3.5 V((f+)) type. Recent → HST observations have shown that component A is itself probably a double or → binary star with a separation of 0.055 arcsec.

HD number.

HD 97950
     
HD 97950

Fr.: HD 97950   

The core of the Galactic → giant H II region, → NGC 3603. It is a multiple object composed of several → massive stars with a collective → spectral type of around WN6+O5. One of the stars, → NGC 3603A-1, is a double-eclipsing binary with an orbital period of 3.77 days. The component masses are 116 Msun for the primary and 89 Msun for the secondary, respectively. The primary WN6ha component of A1 is the most massive star ever directly weighed. A second star, C, has newly been identified, which has been classified as an SB1 binary, and in which only the primary (WN6ha) component is visible. The third star, B, shows constant radial velocities over the observed time interval, and therefore is most likely not a binary. While the primary component of C might have a mass similar to or even greater than that of A1's primary, it is possible that star B, be the most massive member in NGC 3603 and, therefore, the most massive main-sequence star known in the Galaxy (Schnurr et al., 2008, MNRAS, 389, L38).

HD number.

HD number
  عدد ِ HD   
adad-e HD (#)

Fr.: numéro HD   

An identifying number assigned to the stars in the Henry Draper catalog. For example, the star Vega is HD 172167.

Henry Draper system; → number.

He II line
  خط ِ He II   
xatt-e He II

Fr.: raie He II   

Any of the → spectral lines arising from → singly ionized helium in the atmosphere of → O-type and → Wolf-Rayet stars. He II lines are chiefly in absorption, but some of them, such as 4686 Å occur in emission in hotter stars. The presence of He II → absorption lines separates O types from → B-type stars. A number of these He II lines belong to the → Pickering series involving transitions with → principal quantum numbern = 4 and higher. Although the n = 3-4 (4686 Å) transition also belongs to ionized helium and often occurs in these hot stars, it does not belong to the Pickering series because it has a lower landing level quantum number (n = 3). The same goes for n = 2-5 (4026 Å).

helium; → line.

He-strong star
  ستاره‌ی ِ هلیوم-سترگ   
setâre-ye heliom-sotorg

Fr.: étoile forte en hélium   

An early → B-type star showing helium lines with abnormally large equivalent widths. The surface → chemical abundances of He-strong stars are influenced by the presence of a strong → magnetic field, resulting in a He overabundance that typically varies in strength over the stellar surface. Examples include HR 735, HD 184927, and CPD-62°2124.

helium; → strong; → line.

He-weak star
  ستاره‌ی ِ هلیوم-نزار   
setâre-ye heliom-nazâr

Fr.: étoile faible en hélium   

A → chemically peculiar star with very weak helium lines. Examples include 3 Sco, HD 176582, HD 217833, HR 2949, and HD 21699. The He-weak stars do not form a homogeneous group. Some of them display intense Si, or Ti and Sr lines, and are considered a hot extension of the magnetic → Ap/Bp stars. Others show overabundances of P and Ga, typically noted for → HgMn stars. The star HD 139160 belongs to the non-magnetic subgroup of He-weak stars.

helium; → weak; → line.

head
  سر   
sar (#)

Fr.: tête   

1) That part of anything that forms or is situated at the top, summit, or upper end.
2) The → nucleus and surrounding → coma of a → comet.

Head, from O.E. heafod "top of the body," also "chief person" (cf. O.S. hobid; Goth. haubiþ Ger. Haupt "head"), from PIE *kauput- "head;" cf. Skt. kaput-, kapala- "skull;" L. caput "head;" Pers. dialect Lori: kapu "head," kapulek "skull, middle of the head;" Kurd. kapol "skull;" Pashto kaparay "skull."

Sar "head," soru, sorun "horn" (karnâ "a trumpet-like wind instrument," variant sornâ "a wind instrument"); Mid.Pers. sar "head," sru "horn;" Av. sarah- "head," srū- "horn, nail;" cf. Skt. śiras- "head, chief;" Gk. kara "head," karena "head, top," keras "horn;" L. cornu "horn," cerebrum "brain;" P.Gmc. *khurnaz (Ger. Horn, Du. horen; cognate with E. horn, as above, from PIE *ker- "head, horn;" O.E. horn "horn of an animal," also "wind instrument;" E. horn); PIE base *ker- "head, horn, top, summit."

head-tail galaxy
  کهکشان ِ "سر-دم"   
kahkešân-e sar-dom

Fr.: galaxie tête-queue, ~ têtard   

A member of the class of radio galaxies (→ radio galaxy) that have a strong radio emission coming from a bright "head" and a more diffuse emission from a "tail." They are often found in clusters.

head; → tail; → galaxy.

heart
  دل   
del (#)

Fr.: cœur   

1) A hollow muscular organ that pumps the blood through the circulatory system by rhythmic contraction and dilation. In vertebrates there may be up to four chambers (as in humans), with two atria and two ventricles.
2) The heart regarded as the centre of a person's thoughts and emotions, especially love or compassion (OxfordDictionaries.com).

M.E. herte, from O.E. heorte "heart breast, soul, spirit, will, desire; courage; mind, intellect;" cf. O.Saxon herta, O.Frisian herte, O.Norse hjarta, Du. hart, O.H.G. herza, Ger. Herz; cognate with Pers. del, as below; PIE root *kerd- "heart."

Del "heart" (Pashtu z'rrah, zyah; Baluci zirde "heart, mind, soul;" Kurd. zar; Sogd. žyâwar); Mid.Pers. dil; Av. zərəd-; cf. Skt. hrd-; Gk. kardia; L. cor "heart" (Fr. cœur; Sp. corazon, It. cuore); Russ. serdtse; Arm. sirt; E. heart, as above.

heat
  گرما   
garmâ (#)

Fr.: chaleur   

Energy possessed by a substance in the form of kinetic energy of atomic or molecular translation, rotation, or vibration.

Heat, from O.E. hætu, hæto, from P.Gmc. *khaitin- "heat," from *khaitaz "hot" (cf. O.N. hiti, Ger. hitze "heat," Goth. heito "fever").

Garmâ "heat, warmth," from Mid.Pers. garmâg; O.Pers./Av. garəma- "hot, warm;" cf. Skt. gharmah "heat;" Gk. thermos "warm;" L. formus "warm," fornax "oven;" P.Gmc. *warmaz; O.E. wearm; E. warm; O.H.G., Ger. warm; PIE *ghworm-/*ghwerm- "warm."

heat capacity
  گنجایش ِ گرمایی   
gonjâyeš-e garmâyi (#)

Fr.: capacité thermique, ~ calorifique   

The ratio of an amount of heat, dQ, transferred to a body in some process to the corresponding change in the temperature of the body: C = dQ/dT. The heat capacity depends upon the mass of the body, its chemical composition, thermodynamic state, and the kind of process employed to transfer the heat. The word "capacity" may be misleading because it suggests the essentially meaningless statement "the amount of heat a body can hold," whereas what is meant is the heat added per unit temperature rise. → specific heat.

heat; → capacity.

heat conduction
  هازش ِ گرما   
hâzeš-e garmâ

Fr.: conduction de chaleur   

A type of → heat transfer by means of molecular agitation within a material without any motion of the material as a whole.

heat; → conduction.

heat convection
  همبز ِ گرما   
hambaz-e garmâ (#)

Fr.: convection de chaleur   

A type of → heat transfer involving mass motion of a fluid such as air or water when the heated fluid is caused to move away from the source of heat, carrying energy with it.

heat; → convection.

heat death of the Universe
  مرگ ِ گرمایی ِ گیتی   
marg-e garmâyi-ye giti (#)

Fr.: mort thermique de l'Univers   

Assuming that the Universe is a thermodynamically → isolated system, a state of absolute uniformity in the Universe in which all temperature differences would reduce to zero and no energy will be available for use, according to the → second law of thermodynamics. In that condition of maximum → entropy, the Universe would be in a state of unchanging death. First introduced by the German physicist Hermann von Helmholtz (1821-1894) in 1854, on the basis of William Thomson's (1824-1907) idea.

heat; → death; → Universe.

heat of vaporization
  گرمای ِ بخارش   
garmâ-ye boxâreš

Fr.: chaleur de vaporisation   

The amount of heat energy required to transform an amount of a substance from the liquid phase to the gas phase. → molar heat of vaporization.

heat; → vaporization.

heat shield
  سپر ِ گرمایی، گرماسپر   
separ-e garmâyi (#), garmâ-separ

Fr.: bouclier thermique   

A structure that protects against excessive heat, especially that which covers the vulnerable surfaces of a → spacecraft and protects it when re-entering the Earth's atmosphere.

heat; → shield.

heat transfer
  تراوژ ِ گرما   
tarâvaž-e garmâ

Fr.: transfert de chaleur   

The spontaneous transportation of heat through matter, from a region of higher temperature to a region of lower temperature.

heat; → transfer.

heat wave
  چله‌ی ِ تابستان   
celle-ye tâbestân (#)

Fr.: canicule   

Meteorology: A period of several successive days of abnormally hot and usually humid weather occurring in summer.

heat; → wave.

Celle-ye tâbestân literally "the fortieth of summer," i.e. "midsummer," from cellé pertaining to "forty (days)," from cel, cehel, → forty, + tâbestân, → summer.

<< < -es -iv -ti 21- A r abe abs abs acc acc acc act act ada adi adu aff age alc Alf ali all alp alt ama amp ana ang ang ann ano ant ant ape apo app aps arc Arg ari art ass ast ast ast atm ato att aur aut axi B r bac Bal Bar Bar Bay bec Ber Bet Bie bij bin bio bis bla bla blu blu bol Bor bou Bra bre bro Bug C-s cal Cam can car Car Cas cat cav cel cen cer Cha cha cha che cho cir cir cir 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 coo cor Cor cor cos cos cos Cou cou cra cre cro cru cub cur cyc Cyn dar dat day de- dec dec dec def def deg del den dep Des det deu dex die dif dif dil dip dir dis dis dis dis dis div dom Dor dou Dra duc dus dwa dyn e-t ear ecl eco eff Ein Ein ele ele ele ele ele elv emi emp ene enr epa epo equ equ Err Eta Eul eva evo exc exc exh exo exp exp ext ext Fab fai fan fau fel fer fic fil fin fir fla fli flu foc for for for fra fre fre fro fun fuz 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 hep Her hex hig Him hol hor hos hov Hub Hun hyd hyd hyd hyp IC ide ill Ima imp imp inc inc ind ine inf inf inf ini inp ins ins int int int int Int int int int inv ion Iri irr iso iso ite jel Jou JUp Kan Kep Kil kin 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 mar mas mas mat max mea mec meg men mer met met Met mic mid Mil min Mir mix mod mod mol mon mor mov mul mur n-b nan nat nea neg Ner neu new New NGC noc nom non non nor nou nuc nuc num O-p obl obs obs oce Of? ohm omn opa Oph opt opt or orb ord Ori ort osc out ove ozo pal pan par par par par pat pec pen per per per per per Pfu pha pho pho pho phy pie pla Pla pla pla pla plu poi pol pol pol pol por pos pot pow pre pre pre pre pri pri pri pro pro pro pro Pro pro Prz pul pum Pyx 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 rhy rif Rin rob Rom rot rot rum S s Sak San sav sca Sch Sch scr sec sec SED sei sel sem seq sex Sha she sho sid sig sil sim sin siz sla Sma SNR Sof sol sol sol sol sou sou spa spe spe spe spe sph spi spo squ sta sta sta sta ste ste ste sto sto str str sub sub sub sum sup sup sup sup sur sus sym syn syz tan tea tem ten ter the the the the thi thr tid til tip tom tor tou tra tra tra tra Tri tri tru tsu tur two Typ ult umb unc uni uni unk upp urg uvb val var Veg vel ver vib vio vir vis Voi vow wan wat wav WC wea wel whi Wil wir WNh wor X-r Yer Z s zer [C > >>