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With Supernova, designers work seamlessly across multiple design environments. Developers convert every component, style, and screen in customizable front-end code for multiple platforms — with a click. Don't settle for snippets. The jets would also transfer energy into the expanding outer shell, producing a super-luminous supernova. Ultra-stripped supernovae occur when the exploding star has been stripped almost all the way to the metal core, via mass transfer in a close binary.
In the most extreme cases, ultra-stripped supernovae can occur in naked metal cores, barely above the Chandrasekhar mass limit. SN ek  might be an observational example of an ultra-stripped supernova, giving rise to a relatively dim and fast decaying light curve. The nature of ultra-stripped supernovae can be both iron core-collapse and electron capture supernovae, depending on the mass of the collapsing core. The core collapse of some massive stars may not result in a visible supernova.
The main model for this is a sufficiently massive core that the kinetic energy is insufficient to reverse the infall of the outer layers onto a black hole. These events are difficult to detect, but large surveys have detected possible candidates. Only a faint infrared source remains at the star's location. A historic puzzle concerned the source of energy that can maintain the optical supernova glow for months. Although the energy that disrupts each type of supernovae is delivered promptly, the light curves are dominated by subsequent radioactive heating of the rapidly expanding ejecta.
Some have considered rotational energy from the central pulsar. The ejecta gases would dim quickly without some energy input to keep it hot. The intensely radioactive nature of the ejecta gases, which is now known to be correct for most supernovae, was first calculated on sound nucleosynthesis grounds in the late s. It is now known by direct observation that much of the light curve the graph of luminosity as a function of time after the occurrence of a Type II Supernova , such as SN A, is explained by those predicted radioactive decays.
Although the luminous emission consists of optical photons, it is the radioactive power absorbed by the ejected gases that keeps the remnant hot enough to radiate light. The radioactive decay of 56 Ni through its daughters 56 Co to 56 Fe produces gamma-ray photons , primarily of keV and keV, that are absorbed and dominate the heating and thus the luminosity of the ejecta at intermediate times several weeks to late times several months.
Later measurements by space gamma-ray telescopes of the small fraction of the 56 Co and 57 Co gamma rays that escaped the SN A remnant without absorption confirmed earlier predictions that those two radioactive nuclei were the power sources. The visual light curves of the different supernova types all depend at late times on radioactive heating, but they vary in shape and amplitude because of the underlying mechanisms, the way that visible radiation is produced, the epoch of its observation, and the transparency of the ejected material.
The light curves can be significantly different at other wavelengths. For example, at ultraviolet wavelengths there is an early extremely luminous peak lasting only a few hours corresponding to the breakout of the shock launched by the initial event, but that breakout is hardly detectable optically.
The light curves for Type Ia are mostly very uniform, with a consistent maximum absolute magnitude and a relatively steep decline in luminosity. Their optical energy output is driven by radioactive decay of ejected nickel half-life 6 days , which then decays to radioactive cobalt half-life 77 days. These radioisotopes excite the surrounding material to incandescence.
Studies of cosmology today rely on 56 Ni radioactivity providing the energy for the optical brightness of supernovae of Type Ia, which are the "standard candles" of cosmology but whose diagnostic keV and keV gamma rays were first detected only in The light curve continues to decline in the B band while it may show a small shoulder in the visual at about 40 days, but this is only a hint of a secondary maximum that occurs in the infra-red as certain ionised heavy elements recombine to produce infra-red radiation and the ejecta become transparent to it.
The visual light curve continues to decline at a rate slightly greater than the decay rate of the radioactive cobalt which has the longer half-life and controls the later curve , because the ejected material becomes more diffuse and less able to convert the high energy radiation into visual radiation.
After several months, the light curve changes its decline rate again as positron emission becomes dominant from the remaining cobalt, although this portion of the light curve has been little-studied.
Type Ib and Ic light curves are basically similar to Type Ia although with a lower average peak luminosity. The visual light output is again due to radioactive decay being converted into visual radiation, but there is a much lower mass of the created nickel The most luminous Type Ic supernovae are referred to as hypernovae and tend to have broadened light curves in addition to the increased peak luminosity.
The source of the extra energy is thought to be relativistic jets driven by the formation of a rotating black hole, which also produce gamma-ray bursts. The light curves for Type II supernovae are characterised by a much slower decline than Type I, on the order of 0. The visual light output is dominated by kinetic energy rather than radioactive decay for several months, due primarily to the existence of hydrogen in the ejecta from the atmosphere of the supergiant progenitor star. In the initial destruction this hydrogen becomes heated and ionised.
The majority of Type II supernovae show a prolonged plateau in their light curves as this hydrogen recombines, emitting visible light and becoming more transparent. This is then followed by a declining light curve driven by radioactive decay although slower than in Type I supernovae, due to the efficiency of conversion into light by all the hydrogen. In Type II-L the plateau is absent because the progenitor had relatively little hydrogen left in its atmosphere, sufficient to appear in the spectrum but insufficient to produce a noticeable plateau in the light output.
In Type IIb supernovae the hydrogen atmosphere of the progenitor is so depleted thought to be due to tidal stripping by a companion star that the light curve is closer to a Type I supernova and the hydrogen even disappears from the spectrum after several weeks. Type IIn supernovae are characterised by additional narrow spectral lines produced in a dense shell of circumstellar material. Their light curves are generally very broad and extended, occasionally also extremely luminous and referred to as a superluminous supernova.
These light curves are produced by the highly efficient conversion of kinetic energy of the ejecta into electromagnetic radiation by interaction with the dense shell of material.
This only occurs when the material is sufficiently dense and compact, indicating that it has been produced by the progenitor star itself only shortly before the supernova occurs. Large numbers of supernovae have been catalogued and classified to provide distance candles and test models. Average characteristics vary somewhat with distance and type of host galaxy, but can broadly be specified for each supernova type.
A long-standing puzzle surrounding Type II supernovae is why the remaining compact object receives a large velocity away from the epicentre;  pulsars , and thus neutron stars, are observed to have high velocities, and black holes presumably do as well, although they are far harder to observe in isolation.
This indicates an expansion asymmetry, but the mechanism by which momentum is transferred to the compact object remains [update] a puzzle. Proposed explanations for this kick include convection in the collapsing star and jet production during neutron star formation. One possible explanation for this asymmetry is large-scale convection above the core. The convection can create variations in the local abundances of elements, resulting in uneven nuclear burning during the collapse, bounce and resulting expansion.
Another possible explanation is that accretion of gas onto the central neutron star can create a disk that drives highly directional jets, propelling matter at a high velocity out of the star, and driving transverse shocks that completely disrupt the star.
These jets might play a crucial role in the resulting supernova. Initial asymmetries have also been confirmed in Type Ia supernovae through observation.
This result may mean that the initial luminosity of this type of supernova depends on the viewing angle. However, the expansion becomes more symmetrical with the passage of time. Early asymmetries are detectable by measuring the polarization of the emitted light.
Although supernovae are primarily known as luminous events, the electromagnetic radiation they release is almost a minor side-effect. Particularly in the case of core collapse supernovae, the emitted electromagnetic radiation is a tiny fraction of the total energy released during the event.
There is a fundamental difference between the balance of energy production in the different types of supernova. In Type Ia white dwarf detonations, most of the energy is directed into heavy element synthesis and the kinetic energy of the ejecta. Type Ia supernovae derive their energy from a runaway nuclear fusion of a carbon-oxygen white dwarf. The details of the energetics are still not fully understood, but the end result is the ejection of the entire mass of the original star at high kinetic energy.
Around half a solar mass of that mass is 56 Ni generated from silicon burning. These two processes are responsible for the electromagnetic radiation from Type Ia supernovae. In combination with the changing transparency of the ejected material, they produce the rapidly declining light curve. Core collapse supernovae are on average visually fainter than Type Ia supernovae, but the total energy released is far higher.
In these type of supernovae, the gravitational potential energy is converted into kinetic energy that compresses and collapses the core, initially producing electron neutrinos from disintegrating nucleons, followed by all flavours of thermal neutrinos from the super-heated neutron star core.
Kinetic energies and nickel yields are somewhat lower than Type Ia supernovae, hence the lower peak visual luminosity of Type II supernovae, but energy from the de- ionisation of the many solar masses of remaining hydrogen can contribute to a much slower decline in luminosity and produce the plateau phase seen in the majority of core collapse supernovae.
In some core collapse supernovae, fallback onto a black hole drives relativistic jets which may produce a brief energetic and directional burst of gamma rays and also transfers substantial further energy into the ejected material. This is one scenario for producing high luminosity supernovae and is thought to be the cause of Type Ic hypernovae and long duration gamma-ray bursts.
If the relativistic jets are too brief and fail to penetrate the stellar envelope then a low luminosity gamma-ray burst may be produced and the supernova may be sub-luminous.
When a supernova occurs inside a small dense cloud of circumstellar material, it will produce a shock wave that can efficiently convert a high fraction of the kinetic energy into electromagnetic radiation. Even though the initial energy was entirely normal the resulting supernova will have high luminosity and extended duration since it does not rely on exponential radioactive decay.
This type of event may cause Type IIn hypernovae. Although pair-instability supernovae are core collapse supernovae with spectra and light curves similar to Type II-P, the nature after core collapse is more like that of a giant Type Ia with runaway fusion of carbon, oxygen, and silicon. The total energy released by the highest mass events is comparable to other core collapse supernovae but neutrino production is thought to be very low, hence the kinetic and electromagnetic energy released is very high.
The cores of these stars are much larger than any white dwarf and the amount of radioactive nickel and other heavy elements ejected from their cores can be orders of magnitude higher, with consequently high visual luminosity. The supernova classification type is closely tied to the type of star at the time of the collapse.
The occurrence of each type of supernova depends dramatically on the metallicity, and hence the age of the host galaxy. Type Ia supernovae are produced from white dwarf stars in binary systems and occur in all galaxy types. Core collapse supernovae are only found in galaxies undergoing current or very recent star formation, since they result from short-lived massive stars.
They are most commonly found in Type Sc spirals , but also in the arms of other spiral galaxies and in irregular galaxies , especially starburst galaxies. The table shows the progenitor for the main types of core collapse supernova, and the approximate proportions that have been observed in the local neighbourhood.
There are a number of difficulties reconciling modelled and observed stellar evolution leading up to core collapse supernovae. Most progenitors of Type II supernovae are not detected and must be considerably fainter, and presumably less massive. It is now proposed that higher mass red supergiants do not explode as supernovae, but instead evolve back towards hotter temperatures. Several progenitors of Type IIb supernovae have been confirmed, and these were K and G supergiants, plus one A supergiant.
Until just a few decades ago, hot supergiants were not considered likely to explode, but observations have shown otherwise. Blue supergiants form an unexpectedly high proportion of confirmed supernova progenitors, partly due to their high luminosity and easy detection, while not a single Wolf—Rayet progenitor has yet been clearly identified.
One study has shown a possible route for low-luminosity post-red supergiant luminous blue variables to collapse, most likely as a Type IIn supernova. Very luminous progenitors have not been securely identified, despite numerous supernovae being observed near enough that such progenitors would have been clearly imaged. Most of these supernovae are then produced from lower-mass low-luminosity helium stars in binary systems.
A small number would be from rapidly-rotating massive stars, likely corresponding to the highly-energetic Type Ic-BL events that are associated with long-duration gamma-ray bursts. Supernovae are a major source of elements in the interstellar medium from oxygen through to rubidium,    though the theoretical abundances of the elements produced or seen in the spectra varies significantly depending on the various supernova types.
The latter is especially true with electron capture supernovae. The r-process produces highly unstable nuclei that are rich in neutrons and that rapidly beta decay into more stable forms.
But this time, LaMontagne has stepped away from the rootsy folk sound that his fans have come to expect. His singing finally cracks the heady swirl of fuzz-toned guitars like a ray of sun breaking through billowing clouds. Utilizing the resources at his own recording studio, Auerbach helped LaMontagne expand his sonic palette while staying true to his earthy sound.
This song mimics the reverb-drenched recoil of a Joplin-jostled tube band ph and ushers you into audio fun house that can only have been built by a clever studio engineer. OCHS: Ray's previous recordings use resonant acoustic guitar and string sections to create atmosphere behind his singing.
Rossi also did TV and radio work, with his vocals featured in a national ad campaign for McDonald's and the themes for the animated TV shows Beyblade and Rescue Heroes.
Just before the finale of Rock Star: Supernova, the legal battle over the band's name came to a head: the Californian punk-pop band Supernova , which formed in and had their song "Chewbacca" featured on the Clerks soundtrack, filed a federal lawsuit alleging trademark infringement in June against the show's production company, Mark Burnett Productions, as well as the network; Rockstar Entertainment; and Clarke , Newsted , and Lee who were later removed as defendants.
The court sided with the original Supernova , leaving the Rock Star band to find a new name.Supernova started their career as an all-instrumental power trio from Argentina, with a clear symphonic direction in their progressive style, full of academic niches, sometimes elegant and subtle, some other times bombastic and pompous, but always rocky and energetic (they have since added a female vocalist to become a quartet): this is what their debut album, 'Uno Punto Infinito', is all about.