An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 247 Search : star
protoneutron star
  ستاره‌ی ِ پوروا-نوترونی   
setâre-ye purvâ-notroni

Fr.: proto-étoile à neutrons   

A compact, hot, and → neutrino-rich object that results from a → supernova explosion and is a transition between an → iron core and a → neutron star or → black hole. The life span of a protoneutron star is less than one minute.

proto-; → neutron; → star.


Fr.: protoétoile   

A stage in the process of → star formation, after the → gravitational collapse of the dense → pre-stellar core and before the initiation of → nuclear fusion in the central object which will eventually become a star. Protostars are classified into four groups: → Class 0, → Class I, → Class II, and → Class III.

proto- + → star.

Przybylski's star
  ستاره‌ی ِ شبیلسکی   

Fr.: étoile de Przybylski   

A blue star, named HD 101065 or V816 Cen, with an extremely peculiar chemical composition and spectral features. Although the star has a surface temperature very close to that of stars with solar chemical composition, it displays some abundance anomalies typical of much hotter → Ap stars. The spectrum is dominated by a group of lines of → lanthanides, while in the spectra of normal stars with similar temperature the absorption lines of neutral elements from the iron group are predominant. The lanthanides may have abundances 103-104 times solar. The spectrum of Przybylski's star also shows the presence of radioactive → rare earth elements, such as → promethium and → technetium. Moreover, there are numerous strong absorption lines which defy identification. In some spectrum regions unidentified lines are more numerous than known lines. It is also a → roAp star (see, e.g., Gopka et al. 2008, Kinematics and Physics of Celestial Bodies Vol. 24, No. 2, 89).

Named after its discoverer, Antoni Przybylski (1961, Nature 189, 739).

pulsating star
  ستاره‌ی ِ تپنده   
setâre-ye tapandé (#)

Fr.: étoile pulsante   

A type of → variable star that changes its brightness by changing its volume through expansion and contraction. Classical pulsating stars, including → Cepheids, → RR Lyrae, and → Delta Scuti variables, are located in a quite narrow almost vertical region in the → H-R diagram, known as → instability strip. See also → kappa mechanism.

Pulsating, verbal adj. of → pulsate; → star.

quark star
  ستاره‌ی ِ کو‌آرکی   
setâre-ye kuârki

Fr.: étoile de quarks   

A hypothetical star so dense that it is composed of degenerate quarks, a matter denser than that of a neutron star.

quark; → star.

radio star
  رادیو-ستاره، ستاره‌ی ِ رادیویی   
râdio setâré, setâre-ye râdioyi

Fr.: étoile radio   

A star which is a source of emission at radio frequencies. Radio stars include pulsars, flare stars, binary star systems in which mass is transferred from one component to the other, and some X-ray stars.

radio; → star.

rapidly oscillating Ap star
  ستاره‌ی Apی ِ تند نونده   

Fr.: étoile Ap à oscillation rapide   

A chemically peculiar star characterized by the presence of high-frequency non-radial oscillations, with periods that range between about 4 and 16 min. These variations have periods from about 5 to 20 minutes and low amplitudes (B < 10 mmag). They are consistent with acoustic (→ p mode) pulsations of low degree and high radial overtone.

rapid; → -ly; → oscillate; → -ing; → Ap star.

red clump star
  ستاره‌ی ِ گوده‌ی ِ سرخ   
setâre-ye gude-ye sorx

Fr.: étoile du grumeau rouge   

A star on the → horizontal branch which results from the evolution of a → red giant with an initial mass of ~ 1 Msun.

red; → clump; → star.

red HB star
  ستاره‌ی ِ BHR   
setâre-ye RHB

Fr.: étoile RHB   

Same as → red horizontal branch star.

red; → horizontal; → branch; → star.

red horizontal branch star
  ستاره‌ی ِ سرخ ِ شاخه‌ی ِ افقی   
setâre-ye sorx-e šâxe-ye ofoqi

Fr.: étoile rouge de la branche horizontale   

A star found on the red part of the → horizontal branch. According to theoretical models, these stars result from the evolution of stars with a mass around 0.8 Msun, higher than that giving rise to → BHB stars. Upon helium burning in their cores, the remnant envelope of the red giant collapses.

red; → horizontal; → branch; → star.

reddened star
  ستاره‌ی ِ سرخیده   
setâre-ye sorxidé

Fr.: étoile rougie   

A star whose light has undergone → reddening.

Reddened, p.p. of → redden; → star.

RHB star
  ستاره‌ی ِ RHB   
setâre-ye RHB

Fr.: étoile RHB   

Same as → red horizontal branch star.

red; → horizontal; → branch; → star.

roAp star
  ستاره‌ی Apی ِ تند نونده   
setâre-ye Ap-ye tond navandé

Fr.: étoile Ap à oscillation rapide   

Same as → rapidly oscillating Ap star

rapidly oscillating Ap star

rotating star
  ستاره‌ی ِ چرخان، ~ چرخنده   
setâre-ye carxân, ~ carxandé

Fr.: étoile en rotation   

A star that has a non-zero → angular velocity. In a rotating star, the → centrifugal forces reduce the → effective gravity according to the latitude and also introduce deviations from sphericity. In a rotating star, the equations of stellar structure need to be modified. The usual spherical coordinates must be replaced by new coordinates characterizing the → equipotentials. See also → von Zeipel theorem.

rotating; → star.

RR Lyrae star
  ستاره‌ی ِ RR چنگ   
setâre-ye RR Cang

Fr.: étoile RR Lyrae   

A member of a large class of yellow pulsating stars of type A2-F6 with periods less than 1 day. They are similar to Cepheids, except that their periods are much shorter and are less luminous. RR Lyrae stars belong to Population II and are often found in globular clusters (hence one of their older names - cluster variables) or elsewhere in the galactic halo. They are used as distance indicators out to more than 200 kpc.

Lyra; → star.

runaway star
  ستاره‌ی ِ گریزان   
setâre-ye gorizân

Fr.: étoile en fuite   

A massive, young, and hot star that is moving quickly through space. Runaways are probably propelled through space from a binary star when its companion has exploded as a supernova, or ejected from a stellar cluster by the dynamical interactions in the system.

run; away, from O.E. aweg, earlier on weg "on from this (that) place;" → star.

Setâré, → star; gorizân present participle of goriz-, gorixtan "to escape; to flee, run away;" Mid.Pers. virextan; Proto-Iranian *vi-raik, from vi- "apart, asunder" + *raik; Av. raek- "to leave, set free, let off;" Mid./Mod.Pers. reg/rig (in mordé-rig "inheritance"); Skt. ric- "to leave," rinakti "gives up, evacuates;" Gk. leipein "to leave;" L. linquere "to leave;" from PIE *linkw-, from *leikw- "to leave behind" (cf. Goth. leihvan; O.E. lænan "to lend;" O.H.G. lihan "to borrow;" O.N. lan "loan").

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-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.

SAO Star Catalog
  کاتالوگ ِ ستاره‌ای ِ SAO   
kâtâlog-e setâre-yi-ye SAO

Fr.: catalogue SAO   

A general whole-sky catalog compiled by the Smithsonian Astrophysical Observatory which results from the combination of several earlier catalogs. The compilation gives positions and proper motions for 258,997 stars, of which 8,712 are double and 499 variable, with an average distribution of 6 stars per square degree. The star positions have an average standard deviation of 0''.2 at their original epochs (0''.5 at epoch 1963.5). The equinox is 1950.0 and the system that of the FK4.

SAO acrynome of the Smithsonian Astrophysical Observatory; → star; → catalog.

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