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antoniseb
2004-Oct-25, 06:31 PM
Originally posted by VanderL@Oct 25 2004, 06:01 PM
I remember a paper (I'll look it up) where someone is stating 51 reasons (not sure, but it was a lot) why supernovae don't explode.
I posted that link, Here it is:
Fifty-Nine Reasons for a Supernova to not Explode (http://arxiv.org/PS_cache/astro-ph/pdf/0405/0405029.pdf)

I agree that we should take it to a new thread [or summon up the old one], since this isn't really about neutrino oscillation.

VanderL
2004-Oct-25, 06:44 PM
I agree that we should take it to a new thread [or summon up the old one], since this isn't really about neutrino oscillation.

Me too, but if supernovae don't explode the whole question is moot.

Cheers.

suntrack2
2004-Oct-26, 01:36 PM
may be the birth time for new stars yet to come, anton.!

sunil

Duane
2004-Oct-26, 05:56 PM
Ok, read the paper. First of all, it is mistitled--is should read "Five point Nine Reasons..." as that is all the reasons given.

Secondly, this paper talks about the problems they are (were!?!) having modelling a supernova explosion. In essence, the author seems to be saying that the 2d models they were using did not lead to explosions, suggesting there was an element in the modelling that was being missed. He even suggested one answer--neutrino heating behind the shock front.

He went on to say that experiments by CITA using 3d models may overcome the problem they were experiencing getting their models to explode. He also states that neutrino physics used in their modelling were inadaquate.

3-D Explosions: A Meditation on Rotation (and Magnetic Fields) (http://arxiv.org/PS_cache/astro-ph/pdf/0401/0401322.pdf) by Craig Wheeler of the University of Texas is an excellent read on the state of our understanding and modelling of supernova explosions. In it, Wheeler discusses some of the problems they encountered in modelling these tremendous explosions, and some of the answers they discovered to correct their models.

Supernovas do explode VanderL. Spectacularly, I might add.

antoniseb
2004-Oct-26, 07:28 PM
Originally posted by Duane@Oct 26 2004, 05:56 PM
Ok, read the paper.
Right, I thought this was self-evident.
BTW, thanks for the Craig Wheeler paper. Good stuff.

VanderL
2004-Oct-26, 07:53 PM
Supernovas do explode VanderL. Spectacularly, I might add.

Hey don't misunderstand me, I was merely referring to the paper, and I did read the paper. What do you mean 5.9 reasons? What I gather from the paper is that there are 5 major reasons why supernovae don't explode and many minor reasons.
I think the author of the paper wanted to show that the modelling is very difficult and that supernova events are not a simple process (and hence maybe not well understood).
Modelling is not something that convinces me much, every model has assumptions built in and to a degree does what it is "programmed" to do.
Nevertheless, the event we call a supernova is indeed spectacular, but I'm still unconvinced about the nature of such an event.
In my mind some questions remain, how come the remnants are mostly binaries and why can there still be planets around such stars (neutron or any other), where does the structure of the dust shell come from. It takes more observations imo, and not just more computer modelling.

Cheers.

Duane
2004-Oct-26, 08:50 PM
There are many ongoing observations of these amazing objects. Computer modeling is only a tool used to try to understand what is being seen.