These supernovae are counter-intuitive in the sense that normally people think of anti-matter as "bring it into contact with normal matter and it will explode". Here, it's the production of anti-matter that robs pressure and triggers the collapse. But the thing that always baffles me is how something that is collapsing inward like that can explode without leaving a remnant. You have to somehow get all the mass out of the potential well, and it's not easy to take 10 solar masses of material falling inward at an appreciable fraction of the speed of light and turn it around and shoot it out...

Wouldn't the mass in the star's chewy nougat center* escape as energy at the speed of light?

(* IANAP)

From the comments it seems that 'bigger' equals mass, and 'fifty times the size' refers to volume. I was confused too.

That's probably true, but there's also the fact that the majority of the mass of the star escapes as gamma rays and neutrinos, so mass isn't (locally) conserved in these events.

Any of u guys thinking what I'm thinking? This (way cool) process MIGHT be a way to resurrect the Hoyle-Gold-Bondi steady state theory (http://www.aip.org/history/cosmology/ideas/bigbang.htm) - if this guy was 200 times the mass of our sun, who is to say we don't all live in the expanding after-math of just such a (albiet much larger) hyper-nova? Maybe the big bang was something similar to this, and has happened an infinite number of times before, and will again. Just a thought, but I never liked the concept of finite time, for aesthetic reasons. If I'm wrong, please (seriously) let me know how, since just naively it seems that the aftermath of this explosion, if scaled up, is similar to the aftermath of the so-called big bang.

Doesn't seem to me to have any resemblance to the Big Bang, other than involving (kinda) a bang that is big.

This explosion didn't produce time or space.

And this explosion had a centre that you can find after the fact. The `centre' of the big bang was everywhere.

You'd think the largest explosion ever recorded in the universe would make the front page of CNN.