The Near-Earth Threats
A supernova is a huge event and affects everything around it, it is when a star bigger than our sun collapses and is compressed into a sphere the size of the earth, it ends up stealing material from another nearby star and thus starting a runaway nuclear fusion. .
In both cases the explosion is so powerful that it destroys everything around it, the brightness is so intense that it eclipses the light of the galaxy where the exploding star is located, and the flash of the explosion can be seen throughout the planet. universe.
In the end, the object that caused the supernova ends up expelling a large amount of material in the form of a nebula and if the exploding star has more than 10 times the mass of the sun, its cores end up sinking into a black hole.
Among the stars that we know are in the final phase of their lives, the closest is Antares, it is a red supergiant star of class M1, located about 550 light years away, its mass is estimated to be between 15 and 18 solar masses and not the they call it a supergiant for no reason, its size is enormous; If we were to place it in the solar system in the place of the sun, it would swallow all the rocky planets, Mercury, Venus, the Earth, Mars, and it would reach the asteroid belt that is located between the orbits of Mars and Jupiter.
Antares will explode as a supernova and surely its core will transform into a black hole something that astronomers have calculated can happen in a few hundred thousand years, the companion star of Antares and those close to it are doomed, but for luck we are beyond the safety distance.
Betelgeuse will explode long before Antares, it is a little further away, the estimate is that it is about 600 light years away from Earth, it is the second brightest star in the constellation Orion, it is also a red supergiant, it is about 19 times the mass of the Sun and its diameter is about 850 to 905 million kilometers, if we put it in the solar system it would also eat all the rocky planets but the question is when it will explode.
At the end of 2019, the star gave astronomers a huge scare since it suffered a brutal change in its brightness, it faded until the beginning of 2020 when it darkened by 36%.
Some scientists then affirmed that the star could be about to explode, here he clarified that evidently this darkening occurred more than 600 years ago, but we see the universe and we are affected by the things that happen in it when its effects reach us.
We see the moon as it was a little over a second ago, we see the sun as it was a little over 8 minutes ago and we see Betelgeuse as it was about 600 years ago, that does not mean that everything we see in the cosmos it is part of the past and therefore it does not affect us, it all depends on the distance if at this very moment bettergeuse explodes it will take about 25 years to destroy any planet with life that was nearby and about 600 years later it would reach us here on earth The brightness of the explosion.
But at the moment we have not seen the explosion and according to a study carried out by researchers from the University of Australia and published in the astrophysics journal in October 2020, it could still take about 100,000 years to explode, this study offers us probabilities of what what can happen
In reality, we haven't yet seen a star in its final moments before exploding as a supernova, and we don't know all the factors surrounding Betelgeuse or nearby stars like Antares. Within that calculation there is also the possibility, although much less, that both stars explode before their time...
Sources :
https://www.muyinteresante.es/ciencia/20144.html
https://earthsky.org/space/betelgeuse-supergiant-smaller-closer-wont-explode-soon/