Supernovae (simple version)

Supernovae are huge explosions caused by very massive stars, releasing a brightness so intense that it can, for a period, overcome the brightness of entire galaxies. Over time, the brightness and temperature of the explosions slowly decrease. Supernovae mark the "death" of stars in the star cycle. Although they have this violent side, they are responsible for permeating the space with heavier elements and play a role similar to that of a bird, which feeds on seeds and then spreads them on the ground.

If we had a star reasonably close to the solar system, with more than 8 solar masses, that would be a worrying factor. Even if the explosion itself did not reach us, we would still have problems, as the supernova releases a huge amount of gamma rays, which can, in contact with our atmosphere, end our ozone layer, leaving us totally vulnerable to ultraviolet radiation from the Sun. Fortunately, there are no supernova stars around. We see then that the Sun will not end in a supernova, since it does not have the necessary mass.

There are two main classifications for supernovae: Type 1 and Type 2

Type 1 supernovae are given in a binary stellar system (composed of a white dwarf and a companion). The stars in this system interact, so that the matter of the companion star is added to the white dwarf until it reaches the Chandrasekhar limit (1.44 solar masses). At this point, the degeneracy pressure of electrons (which is what prevents the dense star from collapsing) can not contain gravity-induced collapse, so that the white dwarf becomes a neutron star or a black hole (depending on the pasta). In short, the "stealing" and aggregation of the mass of the neighboring star condemns our "thief".

Supernovae type 2 occur in stars that have, on average, more than 8 solar masses. When the process of nuclear fusion ends, the star begins to contract because of its gravity, generating a supernova and remnants.

The remnants of supernovae are a plate full of wonders. Huge clouds of dust of the most varied colors (corresponding to the elements created in the heart of the star) mark the space, giving a contrast to what appears to be the eternal emptiness. Fantastic neutron stars rotating under their axis dozens of times per second (that's right, per second!) Due to the conservation of angular momentum and the "cosmic monsters" (black holes) may be the remnants of the collapsed star; as mentioned, being determined by the mass of the star before collapse.

We see thus that supernovae are proofs that nothing, not even stars, last forever; but they also show us that from a perishing star we have the fertilization of the cosmos, with the scattering of the matter produced in the galactic furnaces (stars), permeating space with elements that enabled the emergence of life. We conclude by quoting Carl Sagan for a brief reflection:

"The cosmos is within us. We are made of dust from the stars. We are a means of the Universe to know each other. "

Material of reference: 50 astronomy ideas you really need to know / From the atom to the black hole / https://en.wikipedia.org/wiki/Supernova