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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Number of Results: 3 Search : pulsational
pulsational
  تپشی   
tapeši

Fr.: pulsationnel   

Of or pertaining to → pulsation. → pulsational instability; → pulsational pair-instability supernova.

pulsation; → -al

pulsational instability
  ناپایداری ِ تپشی   
nâpâydâri-ye tapeši

Fr.: instabilité pulsationnelle   

A term used to describe irregularly spaced, fine-scale structure in optically thick rings. The process relies on a combination of viscosity and self-gravity of ring material to produce this fine structure. Also known as overstability (Ellis et al., 2007, Planetary Ring Systems, Springer).

pulsational; → instability.

pulsational pair-instability supernova
  ابر-نووای ِ ناپایداری ِ تپشی ِ جفت، اَبَر-نو‌اختر ~ ~ ~   
abar-novâ-ye nâpâydâri-ye tapeši-ye joft, abar-now-axtar-e ~ ~ ~

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.