Don’t explode, it’s too easy.At least not as a supernova.
In order to explode as a supernova, a very massive star must have used up its hydrogen supply to such an extent that hydrogen burning is no longer possible.Then it burns helium to carbon for a relatively short period of time, but this does not bring much energy. The star needs a lot of energy to avoid collapsing under its own mass. Only the energy from the fusion reactions keeps the star alive as a plasma ball.
After the helium is used up, carbon is fused.Carbon becomes neon and oxygen. This in turn becomes silicon, and silicon eventually fuses into iron. Each of these fusion reactions brings less energy to the star, and the burning phases become shorter and shorter. While helium burning with a large star lasts another 500,000 years, oxygen burning lasts only 6 months and silicon burning only lasts one day.
What happens then exceeds our human imagination in terms of dimensions.The remaining core of iron can no longer fuse. In order to ignite the fusion of iron cores, the energy available is no longer sufficient. The core is extremely compacted, the density is 10×11 to 10×14 g/cm3 (compared to gold under normal conditions: 19.3 g/cm3). Since the fusion no longer takes place, there is no radiation that inflates the star matter around the nucleus. The gravitational pull of the massive nucleus can now have an unhindered effect: The matter of the star shells plunges into the interior at high speeds and compacts the core even further until it consists almost exclusively of neutrons. clumped into a single, huge neutron. At this point, it suddenly becomes no longer condensed. The collapsing masses now bounce off the core elastically with full force and form a gigantic shock wave. Immediately after impact, the core can relax and release neutrons. These in turn cause the outward-moving shock wave to heat up and cause fusion reactions to ignite. Since temperature and pressure in this hot gas are gigantic, heavier elements are now merging: copper, silver, gold, uranium, etc. Nuclear fusions heat up the gas even more, increase the pressure and accelerate the shock wave even further.
To be clear, the supernova explosion described is such an extreme event that it can destroy anything within 10 to a few 100 light-years.Of course, not faster than at the speed of light. But the X-rays that such an event emits are at the speed of light. That is, an observer who would wait for the supernova with his measuring device a few light-years away, e.g. in the neighboring planetary system, would have no time to flee: the X-ray flash would take him unprepared and leave nothing to him.
Supernovae occur in stars that have at least 8 solar masses.So the sun is far too light to unleash such fireworks. It will slowly inflate into a red giant star as the hydrogen stock inside runs out and helium begins to accumulate in the core. As a result, it will lose more and more mass. At some point, not enough energy is released inside the sun, due to the slowing hydrogen fusion. As a result, the red giant sun collapses very quickly, so that its nucleus is strongly compacted and the helium fusion can ignite. The whole thing is called helium flash and will make the inner planets (Mercury, Venus, Earth, Mars) glow. So one could already speak of a respectable explosion, even if it looks more like the dropping of a pin to launch the lunar rocket compared to a supernova.