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).
→ super-; → naturalism.
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
The total amount of energy liberated by a → supernova. A typical supernova radiates between 1051 and 1052 → erg, or 1044-45 J (→ joules).
Fr.: explosion de supernova
The very short and violent phenomenon that occurs when a star undergoes → core collapse or → thermonuclear runaway.
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; → progenitor.
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.
Fr.: types de supernova
The classification of supernovae according to the presence or absence of the absorption lines of different chemical elements that appear in their spectra shortly after their explosion. Basically, supernovae come in two main types: those that have hydrogen (Type II, from a very massive star that blows up) and those that do not (Type I, due to thermonuclear runaways in a less massive star). Both types exhibit a wide variety of subclasses. Type Ia lacks hydrogen and presents a singly-ionized silicon (Si II) line at 6150 Å, near peak light. Type Ib has non-ionized helium (He I) line at 5876 Å, and no strong silicon absorption feature near 6150 Å. Type Ic shows weak or no helium lines and no strong silicon absorption feature near 6150 Å. Type II stars also have various subclasses. See also → Type I supernova, → Type Ia supernova, → Type Ib supernova, → Type Ic supernova, → Type II supernova, → Type II-L supernova, → Type II-n supernova, and → Type II-P supernova
Exceeding the usual or prescribed number; extra; additional.
L.L. supernumarius "excess, counted in over" (of soldiers added to a full legion), from L. super numerum "beyond the number," → super- "beyond, over" + numerum, accusative of numerus, → number.
Faršomâr, from far- intensive prefix "much, abundant; elegantly;" also "above, upon, over; forward, along," → pro-, + šomâr, → number.
Fr.: arc-en-ciel surnuméraire
An additional faint arc or series of arcs just below the → primary rainbow. Supernumerary bows are caused by → interference and are more common toward the top of the bow.
→ supernumerary; → rainbow.
1) The act of placing upon; the state of being placed upon.
Barhamneheš, from bar- "on, upon, up" (Mid.Pers. abar; O.Pers. upariy "above; over, upon, according to;" Av. upairi "above, over," upairi.zəma- "located above the earth;" cf. Gk. hyper- "over, above;" L. super-; O.H.G. ubir "over;" PIE base *uper "over") + -ham- "together, with," → syn-, + neheš, → position.
Fr.: principe de superposition
1) Math.: The principle concerned with homogeneous and
non-homogeneous → linear differential equations,
stating that two or more solutions to a linear equation or set of linear equations can be added
together so that their sum is also a solution.
→ superposition; → principle.