Hmm, actually, now I wonder if the red-headed miss is actually his protege or something, he left his work to her when he retired.
Might actually be his -daughter-, and isn't -that- a scary thought?
Uh, that's not how that works. Iron is useless for a fission or fusion bomb, because to fuse it requires more energy than it outputs, and fission isn't much better.
And you can't just... blow up a star by throwing iron at it. You'd need to remove the lower sequence elements. And the amount of mass we are talking about is... immense.
A supernovae isn't the result of trying to fuse iron. It's the result of solar energy output finally exceeding solar gravity holding it together. It's basically a very big hiccup. Which makes it a super inefficient explosion.
As noted above, you are somewhat correct, but also wrong. Once iron starts building up in the core of the star, that's a death sentence. Iron that hot tends to do two things: suck up energy necessary for maintaining the core during fusion into heavier elements, and removal of electrons in the process. This removes -both- legs that the core stands on, electron degeneracy pressure (which keeps White Dwarfs from collapsing further), -and- the heat-energy of the core itself, using gas pressure to support the star's enormous weight.
Without either of those around anymore, the entire star falls inward, with the iron core compressing into a solid mass of neutrons. this process produces so many neutrinos that the energy density is enough to halt the infall of the rest of the star, and -blast- it outwards. If the core's mass at this point is above a certain threshold, then even neutron degeneracy pressure can't keep up (which supports neutron stars as essentially 20km atomic nuclei), then the core collapses a bit further, and the escape velocity at the surface reaches C, and you have a black hole.
As such, Supernovae (at least, core collapse supernovae) are fairly efficient explosions, since roughly 80% of the star's total mass (if not vastly more) gets blasted outwards as a tremendous shockwave of radiation, random new elements, and possibly large chunks of heavy elements, forged in the infernal heat of the supernova's wrath. I'm not sure of the actual percentage of the star's mass that's converted into energy here, but you seem to have gotten the wrong impression:
When a supernova lights off, there's NOTHING LEFT of the star, except the gravitationally compressed core, either as a neutron star, or as a black hole. The supernova is triggered by the CESSATION of energy output, causing a massive gravitational core-collapse and subsequent shockwave through the infalling outer layers creating secondary thermonuclear fusion events. That's where most of the world's elements heavier than iron came from: from the tremendous heat generated when the core-collapse shockwave slammed outwards into the infalling outer layers.
