Type Ia Supernovae: Fusion Explosion Explained

[Astronuc]

And note that one of them, 1987A, occurred in a progenitor that at the time was not even known to be susceptible to going supernova! It seems that every time we get a nearby supernova, we find out something new about supernovae progenitors, and that might be true for the next nearby Ia also. One can't help wondering how supernova physics might change in the next few decades, and what the cosmological consequences might be.

Speaking of which,

SN 1987A was classified as a Type II supernova (SN II) in view of the strong hydrogen lines in its optical spectrum, but because it was the explosion of a blue supergiant (BSG) rather than a red one (RSG), it was an atypical SN II: its light curve did not reach maximum until three months after core collapse and at maximum it was only about 10 percent as luminous as most SNe II.

http://arxiv.org/abs/astro-ph/0611033

See also - http://sn1987a-20th.physics.uci.edu/1330-Podsiadlowski.pdf

Let's be careful to distinguish type Ia from II, and let's keep in mind there are Ib and Ic.

Still we need a nearby type Ia to with some pre-characterization of it's progenitor to provide direct observational evidence of Ia development.

 

[Chronos]

We should limit discussion to Ia supernova. Type II supernova are core collapse events occurring in massive stars - not the detonation event believed responsible for Ia supernova. Anyways, I wonder why WD's are the usual suspects in Ia events. Has any consideration been given to neutron stars as possible Ia progenitors? The mass range of neutron stars vary widely - from less than a solar mass [4U1656+35] to 2 solar masses [PSR J1614-2230]. Do they have 'critical' mass limits? What happens when whatever mass limits they may have is exceeded?

 

[Ken G]

Anyways, I wonder why WD's are the usual suspects in Ia events. Has any consideration been given to neutron stars as possible Ia progenitors? The mass range of neutron stars vary widely - from less than a solar mass [4U1656+35] to 2 solar masses [PSR J1614-2230]. Do they have 'critical' mass limits? What happens when whatever mass limits they may have is exceeded?

Neutron stars do have mass limits, usually between 2 and 3 solar masses, and would collapse if they exceeded that limit. But they wouldn't make Ia SNs, because they would look like a bare core collapse (no envelope to blow off), and would not have time to do what would have to be done to those neutrons to get them to fuse. The collapse time would be less than a second once the mass limit was exceeded, so it would just fall right into a black hole, I imagine without much ado, beyond a burst of X-rays from the accretion disk.

 

[ibysaiyan]

We should limit discussion to Ia supernova. Type II supernova are core collapse events occurring in massive stars - not the detonation event believed responsible for Ia supernova. Anyways, I wonder why WD's are the usual suspects in Ia events. Has any consideration been given to neutron stars as possible Ia progenitors? The mass range of neutron stars vary widely - from less than a solar mass [4U1656+35] to 2 solar masses [PSR J1614-2230]. Do they have 'critical' mass limits? What happens when whatever mass limits they may have is exceeded?

Yes,they do have a mass limit which I believe is called : Tolman–Oppenheimer–Volkoff limit.
Ranging about 1.5-3 solar masses .Above this limit neutron degeneracy pressure is unable to withstand the inward gravitational force as a result it collapses.