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srikar97
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Both of them have the same binary system with a white dwarf and a companion star which result in the same bang so what actually is the difference between type 1a supernovae and a novae?
The current view among astronomers who model Type Ia supernova explosions is that this limit is never actually attained, however, so that collapse is never initiated. Instead, the increase in pressure and density due to the increasing weight raises the temperature of the core,[3] and as the white dwarf approaches to within about 1% of the limit,[11] a period of convection ensues, lasting approximately 1,000 years.[12] At some point in this simmering phase, a deflagration flame front is born, powered by carbon fusion. The details of the ignition are still unknown, including the location and number of points where the flame begins.[13] Oxygen fusion is initiated shortly thereafter, but this fuel is not consumed as completely as carbon.[14]
Once fusion has begun, the temperature of the white dwarf starts to rise. A main sequence star supported by thermal pressure would expand and cool in order to counter-balance an increase in thermal energy. However, degeneracy pressure is independent of temperature; the white dwarf is unable to regulate the burning process in the manner of normal stars, and is vulnerable to a runaway fusion reaction. The flame accelerates dramatically, in part due to the Rayleigh–Taylor instability and interactions with turbulence. It is still a matter of considerable debate whether this flame transforms into a supersonic detonation from a subsonic deflagration.[12][15]
Regardless of the exact details of nuclear burning, it is generally accepted that a substantial fraction of the carbon and oxygen in the white dwarf is burned into heavier elements within a period of only a few seconds,[14] raising the internal temperature to billions of degrees. This energy release from thermonuclear burning (1–2×10^44 J[4]) is more than enough to unbind the star; that is, the individual particles making up the white dwarf gain enough kinetic energy that they are all able to fly apart from each other. The star explodes violently and releases a shock wave in which matter is typically ejected at speeds on the order of 5000–20,000 km/s, or roughly up to 6% of the speed of light. The energy released in the explosion also causes an extreme increase in luminosity. The typical visual absolute magnitude of Type Ia supernovae is Mv = −19.3 (about 5 billion times brighter than the Sun), with little variation.[12] Whether or not the supernova remnant remains bound to its companion depends on the amount of mass ejected
Chronos said:A type Ia supernova is fairly unique because they detonate right at the Chandrasekhar mass limit, making them ideal standard candles.
There is still a lot of debate over the mechanics behind a Ia event, but, little dissent over their intrinsic luminosity.
Chronos said:A type Ia supernova is fairly unique because they detonate right at the Chandrasekhar mass limit, making them ideal standard candles.
srikar97 said:well..they are used as a standard candle and moreover the reports are mostly correct but what if a cosmologist gets confused whether it is a supernova or just a nova before doing his research?
srikar97 said:How can one classify supernovae/novae via spectrum?
The main difference between type 1a supernovae and a novae is the cause of their explosions. Type 1a supernovae occur when a white dwarf star accretes mass from a companion star, causing it to exceed its Chandrasekhar limit and explode. Novae, on the other hand, occur when a white dwarf star siphons off material from a companion star, causing a thermonuclear explosion on its surface.
The light curves of type 1a supernovae and novae differ in their shape and duration. Type 1a supernovae have a characteristic bell-shaped light curve with a gradual rise to peak brightness and a slow decline. Novae, on the other hand, have a much shorter and more erratic light curve with a rapid increase in brightness followed by a quick decline.
Yes, type 1a supernovae and novae can be used as standard candles for measuring distances in the universe. However, type 1a supernovae are considered more reliable standard candles as they have a more consistent luminosity and are less affected by external factors such as the composition of the surrounding environment.
Yes, there are differences in the elements produced by type 1a supernovae and novae. Type 1a supernovae produce a large amount of iron, while novae produce a range of elements including carbon, nitrogen, and oxygen. This is due to the different mechanisms of their explosions.
Yes, type 1a supernovae and novae have different implications for the evolution of galaxies. Type 1a supernovae are important for the production of heavy elements and play a significant role in the chemical enrichment of galaxies. On the other hand, novae can contribute to the formation of new stars through their expulsion of material into the interstellar medium.