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.
supermassive black hole (SMBH)
Fr.: trou noir supermassif
A → black hole of tremendous mass, equivalent to those of millions or even billions of stars, which is believed to exist and occupy the centers of many galaxies. The supermassive black hole residing in the center of our → Milky Way Galaxy is the object → Sgr A* with a mass of 4 x 106→ solar masses within a radius of 100 → astronomical units.
supermassive neutron star
setâre-ye notroni-ye abar-porjerm
Fr.: étoile à neutron supermassive
Fr.: étoile supermassive
A star with an initial mass over about 120 solar masses. The existence of such stars is the present Universe is not confirmed. Such stars were proposed as an explanation for very bright O type stars in the Large Magellanic Cloud, but these are now known to be clusters of ordinary O stars. → very massive star; → massive star.
Fr.: super lune
Same as → perigee full Moon.
A generalization of the concept of multiplet to the case when there are several quantum numbers that describe the quantum-mechanical states.
1) Of, pertaining to, or being above or beyond what is natural; unexplainable by natural;
Belief in the doctrine of supernatural or divine agency as manifested in the world, in human events, religious revelation, etc. (Dictionary.com).
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 the → solar luminosity. 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 object. In → white dwarfs forming → 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. Consequently, the white dwarf collapses in a → supernova explosion to form a neutron star. There are several → supernova types.
Fr.: candidat supernova
A star which according to observational data could become a supernova.
Fr.: éjecta de supernova
The material ejected by a → supernova explosion.
Fr.: énergie de supernova
Fr.: explosion de supernova
Fr.: rétroaction des supenovae
1) The process whereby the energy and matter contained in a → supernova
are injected into the → interstellar medium after the
→ supernova explosion.
The → thermal energy injected into the ISM serves to
→ suppress → star formation, while
→ heavy elements → nucleosynthesized
inside SNe tend to enhance star formation.
Fr.: supernova imposteuse
A brilliant burst of light that would suggest a → supernova explosion, but analysis of the star's → light curve, → spectrum, and → luminosity rules it out as a genuine supernova. Energetic → outbursts of → massive stars are often labeled as "supernova impostors" (Van Dyk et al. 2000). Many of these giant eruptions are spectroscopically similar to → Type II-n supernovae and thus receive a supernova (SN) designation, but are later recognized as subluminous or their spectra and light curves do not develop like true supernovae. Consequently, they are often referred to as "supernova impostors." These impostors or giant eruptions are examples of high → mass loss episodes apparently from evolved massive stars. Authors often refer to them as → Luminous Blue Variables (LBVs), but these giant eruptions are distinctly different from LBV/→ S Doradus variability in which the star does not increase in luminosity and the eruption or maximum light can last for several years. The mechanisms triggering these events are not yet fully understood (see, e.g., Humphreys et al., 2016, arXiv:1606.04959v1).
supernova light curve
xam-e nur-e abarnovâ, ~ ~ abar-now-axtar
Fr.: courbe de lumière de supernova
The graph of luminosity as a function of time after a → supernova explosion. The → light curve goes up rapidly to a → peak luminosity, then decays away slowly over time, with different rates, depending on the → supernova type. The temporal evolution of a supernova's luminosity contains important information on the physical processes driving the explosion. The observed → bolometric light curves provide a measure of the total output of converted radiation of → Type Ia supernovae, and hence serve as a crucial link to theoretical models of the explosion and evolution.
Fr.: progéniteur de supernova
A star which is at the origin of a supernova phenomenon.
supernova remnant (SNR)
Fr.: reste de supernova
The body of expanding gas ejected at a speed of about 10,000 km s-1 by a → supernova explosion, observed as a diffuse → gaseous nebula, often with a → shell-like structure. Supernova remnants are generally powerful → radio sources. The evolution of the SNR can be divided into different phases according to the dominant physical processes. Simplified models are made for the first stages, to get an idea of typical time scales, expansion velocities, and sizes. The three main phases are: 1) the → free expansion phase, 2) the → Sedov-Taylor phase, and 3) the → snowplow phase.
šok de abar-now-axtar, toš-e ~
Fr.: choc de supernova
A → shock wave that forms when the inner → iron core (of ~ 0.5 Msun) → collapses until it reaches densities in excess of → nuclear density. At this point the pressure rises dramatically and resists further collapse. The homologous core bounces and drives out a shock wave that works its way through the remainder of the initial iron core. The small compressibility of nuclear matter halts the infall of the innermost core by an elastic collective bounce whose kinetic energy is almost immediately depleted by the → photodisintegration of heavy nuclei and the emission of → neutrinos.