An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < cor sup > >>

Number of Results: 37 Search : nova
core-collapse supernova
  اَبَر-نو‌اختر ِ رمبش ِ مغزه   
abar-now-axtar-e rombeš-e maqzé

Fr.: supernova à effondrement de coeur   

A supernova arising from the → core collapse of a → massive star. Same as → Type Ib, → Type Ic, or → Type II supernova.

core; → collapse; → supernova.

delayed supernova explosion
  اسکفت ِ بادرنگ ِ اَبَر-نو‌اختر   
oskaft-e bâderang-e abar-now-axtar

Fr.: explosion retardée de supernova   

A mechanism predicted by theoretical models of → supernova explosion that operates after the → supernova shock fails to deliver a → prompt supernova explosion. The delayed supernova explosion mechanism assumes that a few tenth of a second after the → iron core collapse, the supernova shock is stalled due to energy dissipation. The material between the → protoneutron star and the stalled shock is mainly disintegrated into neutrons and protons due to the high temperatures (a few MeV) in this region. As the → neutrinos coming from the protoneutron star run through this material, a fraction of the neutrinos are captured by the → nucleons, and their energy is deposited in the material. As a result, the material behind the shock is heated by the neutrinos. If this neutrino heating is efficient enough, the stalled shock can be reinvigorated to bring about a supernova explosion.

delay; → supernova; → explosion.

dwarf nova
  نو‌اختر ِ کوتوله   
nowaxtar-e kutulé

Fr.: nova naine   

A class of → novae and → cataclysmic variables that have multiple observed → eruptions. Their prototype is → U Geminorum star. Optically, dwarf nova eruptions have amplitudes of 2-6 mag in V, a duration of a few to 20 days and a recurrence time-scale of weeks to years. Dwarf novae are thought to be → semidetached binary stars consisting of a → white dwarf  → primary accreting via → Roche lobe overflow from a → companion which is usually a → late-type, generally → main-sequence star. DN outbursts are usually attributed to the release of gravitational energy resulting from an → instability in the → accretion disk or by sudden mass transfers through the disk.

dwarf; → nova.

historical supernova
  اَبَر-نو‌اَختر ِ تاریخی   
abar-now-axtar-e târixi (#)

Fr.: supernova historique   

A supernova event recorded in the course of history before the invention of the telescope. The well recorded supernovae of this small group are SN 185, SN 1006, SN 1054 (→ Crab Nebula), SN 1181, SN 1572 (→ Tycho's star), and SN 1604 (→ Kepler's star).

historical; → supernova.


Fr.: hypernova   

A highly energetic → supernova explosion. This phenomenon, which is more violent than a typical → supernova event, is accompanied by a → gamma-ray burst.

hyper-; → nova.

luminous red nova (LRN)
  نو‌اختر ِ سرخ ِ تابان   
now-axtar-e sorx-e tâbân

Fr.: nova rouge lumineuse   

A stellar explosion thought to be caused by the → merger of stars in a → binary system. They are characterized by a distinct red color, and a → light curve that lingers with resurgent brightness in the → infrared. The luminosity of the explosion is between that of a → supernova and a → nova.

luminous; → red; → nova


Fr.: macronova   

A stellar → explosion with energies between those of a → nova and a → supernova and observationally distinguished by being brighter than a typical nova (MV ~ -8 mag) but fainter than a typical supernova (MV ~ -19 mag) (Kulkarni 2005; arXiv:astro-ph/0510256).

macro-; → nova.

now-axtar (#)

Fr.: nova   

A star that experiences a sudden increase in luminosity, by a s much as 106. The outburst ejects a shell of matter but does not disrupt the star.

Nova, from L. stella nova "new star," from stellastar + nova, fem. of novusnew.

Now-axtar "new star," from now, → new, + axtar, → astro-.

pair-instability supernova
  اَبَر-نو‌اختر ِ ناپایداری ِ جفت   
abar-now-axtar-e nâpâydâri-ye joft

Fr.: supernova à instabilité de paires   

A special type of → supernova that would result from the → pair instability in → supermassive stars with a mass range between 140 and 260 Msun in a low → metallicity environment. Such objects descended from the → Population III stars in the early history of the Universe. Such supernovae are the most powerful thermonuclear explosions in the Universe. Pair-instability supernovae may have played an important role in the synthesis of → heavy elements. Moreover, the energetic feedback of the processed elements to their surroundings could have affected the structure and evolution of the early Universe (See, e.g., Fryer et al. 2001, ApJ 550, 372; Heger & Woosley 2002, ApJ 567, 532). See also → pulsational pair-instability supernova.

pair; → instability; → supernova.


Fr.: post-nova   

The stage following a nova outburst, when the star has returned to a quiescent state.

post-; → nova.

pre-nova stage
  گامه‌ی ِ پیش-نو-اختری   
gâme-ye piš-now-axtari

Fr.: étape pré-nova   

The stage of a star before its eruption to become a nova.

pre-; → nova; → stage.

prompt supernova explosion
  اسکفت ِ تند ِ نو‌اختر، ~ بی‌درنگ ِ ~   
oskaft-e tond-e abar-now-axtar, ~ biderang-e ~

Fr.: explosion rapide de supernova   

A mechanism predicted by theoretical models of → supernova explosion in the case when the → supernova shock breaks through the outer edge of the collapsing → iron core before losing all of its energy (through → photodisintegration of the iron nuclei) and manages to expel the stellar envelope. Compare with → delayed supernova explosion.

prompt; → supernova; → explosion. See also → delay.

pulsational pair-instability supernova
  اَبَر-نو‌اختر ِ ناپایداری ِ تپشی ِ جفت   
abar-now-axtar-e nâpâydâri-ye tapeši-ye joft

Fr.: supernova à instabilité pulsationnelle de paires   

A → supernova resulting from the → pair instability that generates several successive explosions. According to models, a first pulse ejects many solar masses of hydrogen layers as a shell. After the first explosion, the remaining core contracts and searches for a stable burning state. When the next explosion occurs a few years later, several solar masses of material are again ejected, which collide with the earlier ejecta. This collision can radiate 1050 erg of light, about a factor of ten more than an ordinary → core-collapse supernova. After each pulse, the remaining core contracts, radiates neutrinos and light, and searches again for a stable burning state. Later ejections have lower mass, but have higher energy. They quickly catch up with the first shell, where the collision dissipates most of their kinetic energy as radiation. The first SNe from → Population III stars are likely due to pulsational pair instability (Woosley et al. 2007, Nature 450, 390). See also → pair-instability supernova.

pulsational; → pair; → instability.

recurrent nova
  نو‌اختر ِ باز‌آیند   
now-axtar-e bâzâyand

Fr.: nova récurrente   

A → cataclysmic variable star that undergoes → outbursts similar to those found in novae.

recurrent; → nova.

slow nova
  نو-اختر ِ آهسته   
now-axtar-e âhesté

Fr.: nova lente   

A type of nova whose light curve exhibits a characteristically slow development, having a rise time of several days, maximum of several weeks, and slower decline.

slow; → nova.

superluminous supernova
  ابر-نو-اختر ِ ابر-تابان   
abarnowaxtar-e abartâbân

Fr.: supernova superlumineuse   

A → supernova with an → absolute magnitude of about -22 in optical. Examples of these newly discovered SNe include SN 2006gy, SN 2005ap, and SNe 2003ma. The nature of these objects is poorly known. Some of them are powered by the circumstellar interaction, or by the shock breakout from the dense circumstellar medium, as suggested by the presence of narrow emission lines in superluminous → Type II-N supernovae. It is also argued that superluminous SNe could be powered by a large amount of 56Ni which is synthesized as a result of energetic → core-collapse supernovae. Other scenarios include the interaction between shells ejected by the pulsational → pair-instability. See, e.g. Tanaka et al. 2012, MNRAS 422, 2675, arXiv:1202.3610, and references therein.

superluminous; → supernova.


Fr.: supernova   

A violent stellar explosion which blows off all or most of the star's material at high velocity leaving a compact stellar remnant such as a neutron star or black hole. At maximum light, the supernova can have luminosity about 108 or 109 times that of the Sun. The phenomenon results from the later evolution of stars when an instability sets in the core following the nucleosynthesis of iron. In massive stars, the supernova occurs when the star has used up all its available nuclear fuel and it reaches a lower energy state through gravitational collapse to form a more compact star. In white dwarf stars in binary systems, accretion of mass onto the surface of a neutron star can be sufficient to take the star over the upper mass limit for stability as a white dwarf and it collapses to form a neutron star resulting in a → supernova explosion. See also → supernova types.

super-; → nove.

supernova candidate
  نامزد ِ اَبَر-نو‌اختر   
nâmzad-e abar-now-axtar

Fr.: candidat supernova   

A star which according to observational data could become a supernova.

supernova; → candidate.

supernova ejecta
  اشاناک ِ اَبَر-نو‌اختر   
ešânâk-e abar-now-axtar

Fr.: éjecta de supernova   

The material ejected by a → supernova explosion.

supernova; → ejecta.

supernova energy
  کاروژ ِ اَبَر-نو‌اختر   
kâruž-e abar-now-axtar

Fr.: énergie de supernova   

The total amount of energy liberated by a → supernova. A typical supernova radiates between 1051 and 1052  → erg, or 1044-45 J (→ joules).

supernova; → energy.

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