What is the similarity between nova and Type Ia supernova?

Question

Comparing the two different stars in galaxy

Answer 1

Hi. Well, you have lots of words to read. By 'nova' I assume you mean a supernova. The similarities are that they both cause a huge increase in brightness of the exploding star and both form higher order elements. Type 1a is important because they are all nearly equal in actual brightness and can be used to gage distance.

Answer 2

Both a nova and Type Ia supernova occur only in binary stars where one of the stars is a white dwarf and the other is a giant star.

Answer 3

Type Ia

"The most commonly accepted theory of this type of supernovae is that they are the result of a carbon-oxygen white dwarf accreting matter from a nearby companion star, typically a red giant.[16]" If the accretion continues long enough, the white dwarf may eventually approach the Chandrasekhar limit (1.44 solar masses), the maximum mass that can be supported by electron degeneracy pressure,[17] beyond which the white dwarf would collapse to form a neutron star (if nothing intervened to stop the process).[18]

The current view is that this limit is never actually attained, so that collapse is never initiated. Instead, the increase in pressure raises the temperature near the center, and a period of convection lasting approximately 1,000 years[19] begins. At some point in this simmering phase, a deflagration flame front powered by carbon fusion is born, although the details of the ignition—the location and number of points where the flame begins—is still unknown.[20] Oxygen fusion is initiated shortly thereafter, but this fuel is not consumed as completely as carbon.[21]

Once fusion begins, the white dwarf quickly discovers that its dependence on degeneracy pressure (rather than thermal pressure) to support its weight against gravity carries a heavy price. It is unable to respond to the initial temperature increase by expanding and cooling (because degeneracy pressure is independent of temperature), and thus cannot regulate the burning in the manner of normal stars. The flame accelerates dramatically, through the Rayleigh-Taylor instability and interactions with turbulence. It is still a matter of considerable debate as to whether this flame transitions from a subsonic deflagration into a supersonic detonation.[19]

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,[21] raising the internal temperature to billions of degrees.

This energy release from thermonuclear burning (≈1046 joules)[21] 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 5-20,000 km/s, or roughly 3% of the speed of light. The energy released in the explosion also causes an extreme increase in luminosity. The typical absolute magnitude of Type Ia supernovae is -19.3 (≈ 5 billion times brighter than Sol), with little variation.[19]
Multiwavelength X-ray image of SN 1572 or Tycho's Nova (NASA/CXC/Rutgers/J.Warren & J.Hughes et al.)
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Multiwavelength X-ray image of SN 1572 or Tycho's Nova (NASA/CXC/Rutgers/J.Warren & J.Hughes et al.)

The theory of this type of supernovae is similar to that of novae, in which a white dwarf accretes matter more slowly and does not approach the Chandrasekhar limit. In the case of a nova, the infalling matter causes a hydrogen fusion surface explosion that does not disrupt the star.[19]

[edit] Formation

Unlike the other types of supernovae, Type Ia supernovae generally occur in all types of galaxies, including ellipticals. They show no preference for regions of current stellar formation.[22] As white dwarf stars form at the end of a star's main sequence evolutionary period, such a long-lived star system may have wandered far from the region where it originally formed. Thereafter a close binary system may spend another million years in the mass transfer stage (possibly forming persistent nova outbursts) before the conditions are ripe for a Type Ia supernova to occur.[23]

A second possible, but much less likely, mechanism for triggering a Type Ia supernova is the merger of two white dwarfs. In such a case, the total mass would not be constrained by the Chandrasekhar limit. This is one of several explanations proposed for the anomalously massive (2 solar mass) progenitor of the "Champagne Supernova" (SN 2003fg or SNLS-03D3bb).[24]

Collisions of solitary stars within our galaxy are thought to occur only once every 107–1013 years; far less frequently than the appearance of novae.[25] However, collisions occur with greater frequency in the dense core regions of globular clusters.[26] (C.f. blue stragglers.) A likely scenario is a collision with a binary star system, or between two binary systems containing white dwarfs. This collision can leave behind a close binary system of two white dwarfs. Their orbit decays and they merge together through their shared envelope.[27]

[edit] Light curve

Type Ia supernovae have a characteristic light curve, their graph of luminosity as a function of time after the explosion. Near the time of maximum luminosity, the spectrum contains lines of intermediate-mass elements from oxygen to calcium; these are the main constituents of the outer layers of the star. Months after the explosion, when the outer layers have expanded to the point of transparency, the spectrum is dominated by light emitted by material near the core of the star, heavy elements synthesized during the explosion, most prominently iron-group elements. The radioactive decay of Nickel-56 through Cobalt-56 to Iron-56 produces high-energy photons which dominate the energy output of the ejecta at intermediate to late times.[19]

The similarity in the absolute luminosity profiles of nearly all known Type Ia supernovae has led to their use as a standard candle in extragalactic astronomy.[28] The cause of this uniformity in the luminosity curve is still an open question. In 1998, observations of Type Ia supernovae indicated the unexpected result that the universe seems to undergo an accelerating expansion.[5][6]

Source: Wikipedia: Nova's
http://en.wikipedia.org/wiki/Supernova

So, this type would take 2 stars to go Supernova while others would take one.

Answer 4

something gotta do with the critical masses.......supernova is heavier and gives bigger implosion....

Answer 5

It is similar to sexy and super sexy.