The answer above say it nicely.
Science would be confused (as in, terribly and physics-defyingly confused). Yes. Completely. If they had time to be.
To see why, we need a basic point about quantum physics. Without going into great detail, some particles (known as fermions, and including electrons) simply cannot be packed "too close" because of quantum effects. When forced together under pressure or by some force, this effect manifests as a force arising between them (known as "degeneracy force/pressure") , that resists the force that would otherwise pack them closer. This is the reason behind everyday matter taking up space, it's why chemistry and chemical reactions happen (in basic terms the Periodic Table is largely related to electron "shells" as they are loosely called which is why alkali metals share similar properties, as do halogens, and so on).
In a star, the fusion reactions take place in the core (or for a large star, in layers deep in the star). Although massive and generating a very large gravitional force inward, the star doesn't collapse for 2 reasons - 1) heat, 2) the "exclusion effect" described above, both counteract gravity.
Now consider the same star, when its core runs out of fusable material. If it's below a certain size, the forces between particles (from degeneracy pressure) can counteract the inward gravity indefinitely, alone. So below a certain size, the star simply won't collapse.... and a supernova is a stellar collapse phenomenon. No collapse, no sn. Turns out the size needed for exclusion forces alone, not to be able too counteract gravity, is about 8x the suns mass. So the sun simply can't go supernova, now or ever, left to itself.
The most common way for a star under 8 solar masses to become a supernova is if it isn't left to itself - it gets extra mass from a companion star. One day, enough mass reached, collapse! - called a type 1 (or 1a) supernova. The sun doesn't have a companion star though.
However, if the star is larger than 8 solar masses, its different. There are 3 or 4 possible/known versions of "different", 2 of them give a supernova.
Around 8-9 solar masses isn't quite enough to directly trigger a supernova, but it is enough to trigger a process that gradually removes free electrons from the core, faster than they can be replaced. This reduces the exclusion force instead, so one day - bang! Collapse and supernova.
About 10+ solar masses it's more direct. The star burns all its fuel (in a well-known sequence that sees it fusing its previous fusion products in layers, at even higher temperatures), but it finally runs out of fusable fuel, and it already has a massive enough core that exclusion forces can't counter its own inward gravity without the additional outward forces of active fusion processes. So it collapses. But you only get a supernova from this process up to a certain point - if the star was very, very massive it doesn't get a chance to sn, it either collapses directly to a black hole (or weakly supernova's then collapses back into one), or it blows itself apart via pair production fluctuations. (That's cases 3+4).
Whatever the route, the supernova process broadly follows a similar path. The core - that's the innermost part of the star, not all of it - suddenly finds it can't sustain itself against the inward force of gravity, even with the exclusion principle at work. It suddenly kind of detaches from the rest of the star and collapses inward - and by "suddenly" think in terms of milliseconds and 3/4 of the speed of light. Massive heating, massive outburst of energy (largely in the form of neutrinos), the neutrinos unlike photons can escape from the core easily and add a further runaway loss of energy and support to the collapsing core, it becomes more likely that electrons combine with protons forming neutrons removing even more degeneracy pressure, in the extreme temperatures and pressures elements more massive than iron and silicon are created, 10% or so of its entire mass is converted to energy - and then the inward free-falling core reaches a density around that of neutrons at its heart, and this, finally, stops the collapse. Instead (and we don't fully know the mechanics of it), the infalling core rebounds, and blasts the blissfully unaware outer parts of the star into space in a huge detonation, leaving behind the newly formed neutron core as a neutron star or other similar object, and a nebula of expanding gas.
But that, alas, is one thing our own star will (almost certainly) never do.
What would we see, if it could and did? Well... the best description I ever heard was something like this: "what would deliver the brighter flash to your retina (assuming visibility) - a 50 megaton thermonuclear weapon detonating on your eyeball, or a star going supernova at the same distance as our sun?"
(the comment below says this is from xkcd, and so it is)
One guess :) And by something like a billion times.