Supernovas and Hypernovas what is their Relevance to Stars

Hypernovae and supernovae both begin their lives as stars that are very similar to our own sun.  In order to properly analyze their existence, we should start by describing a supernova.

When a massive star is no longer able to produce energy, meaning that it is not able to continue fusing the nuclei of atoms at its core, it begins to develop a core that is made of iron. Once the iron core has accumulated enough mass, and it can no longer resist the strain of gravity, the core will violently collapse in upon itself. When this takes place, the star will violently expel all of its outer layers. Once this occurs a supernova has been created.

Generally speaking, if the mass of the star is less than 25 times the mass of our own sun, the collapse of the core will only trigger enough pressure to transform its electrons into protons, which actually creates neutrons. The force of the star is still enough to resist gravity so the supernova retains some of its gravitational energy and results in a neutron star.

When the same process occurs in a star that is between 25 and 40 times the mass of our own sun, the same process occurs. However, stars of this size don’t maintain enough energy to completely expel all of their mass, which results in a large portion of it falling back to the surface of the star. As this happens and the star becomes too heavy, all of the gravitational energy is released and it becomes a black hole. The entire process usually takes place over a period of a few weeks to several months, depending on the mass of the star.

If a star is more than 40 times the mass of our sun it is primarily made up of helium and hydrogen. As these starts begin to lose their ability to produce fusion energy, the energy can be projected outward much more efficiently. This is mostly due to the fact that the primary elements that make up the star are extremely light. Because of this absence of weight, as the core of the star collapses in upon itself, the entire balance of the star’s energy is violently released over a matter of minutes and is released in the form of radiation. When this happens, the star will explode directly into a black hole, which releases even more energy in the form of gamma rays. This type of failed star is known as a hypernova.

So, the relevance of supernovae and hypernovae to regular stars, such as our own sun, is the fact that they used to be stars themselves. In fact, our sun will also be heading in this direction in a few million years.


National Aeronautics and Spaace Administration,,