In theory, the Sun is destined to transform once into a mysterious object called a black dwarf. Let us see what these celestial bodies are and how it will turn out for earthlings.
In fact, black dwarfs are the final branch of the evolution of certain stars. Depending on the mass, the star can become a white dwarf, a neutron star and a black hole. Black dwarfs arise from white dwarfs when the latter cool down for a long period of time.
Interestingly, white dwarfs are also called eternal stars (“Do eternal stars exist in the universe?”). The fact is that for the final cooling of a star to 5K it takes about 10 15 years. But the age of our Universe reaches only 13.8 billion years, so the black dwarfs just did not have time to appear.
Stages of evolution of a star
Let's go back to our star. The sun does not have enough mass to explode as a supernova and become a black hole or a neutron star. He will have to go through his evolutionary path, including the red giant stage, the expansion and ejection of layers, after which a white dwarf and the surrounding planetary nebula will appear. Then 10 15 years will pass and the white dwarf (former Sun) will turn into a black dwarf. So how does this turn out for the earth? Well ... the fact is that humanity, and indeed the planet itself, is not destined to exist for about four quadrillion years. Even at the red giant stage, everything on Earth will perish from the heat. We will simply be fried by our own star, swallow up the planet, and humanity will be us until we get as far as possible (rush right away to Pluto).
Let us then imagine that the Sun somehow miraculously passed all the intermediate stages, reduced in size, cooled down and became a black dwarf. How will mankind feel now? Very bad!
We recommend immediately stock up on heaters and lighting, because the entire solar system will plunge into darkness. Fill cabinets with sweaters, because with the light goes and warm. Earthlings are spoiled in terms of temperature, because we were lucky to exist in the habitable zone with comfortable conditions.
But the neighborhood with the brown dwarf in the first week will lower the temperature index on Earth to 0 ° C. In a year, the temperature will reach -100 ° C and will continue to drop further. Oceans will be covered with ice. The only option for survival is to go as deep as possible under the surface, or to have time to dive into the ocean floor and build a colony closer to geothermal sources. In addition, the transformation into a black dwarf will plunge our sky into eternal darkness, and we will finally begin to see that the planet is in an infinitely gloomy outer space. This is all a hypothetical scenario, because the Sun cannot go against the laws of physics and evolution and suddenly become a black dwarf. And although for us this would be a catastrophe, in the framework of the Universe it is an almost imperceptible event. Just the death of a star.