On some occasion, we have all looked up at the sky on a clear country night, and we have wondered how many stars there are in the universe if we already count hundreds of them with the naked eye. Given the great distance that separates us from these stars, the stellar radiation reaches us with years of delay and very weak due to seeing or distortion caused by atmospheric turbulence. All this makes the task of surveying the star map difficult, which still presents difficulties for astronomers today.
A star is a sphere of gas that maintains its shape thanks to the balance between the force of gravity, which contains matter, and the pressure of the plasma, which tends to expand it . Stars are not randomly scattered through space, but as we already know, they are grouped into galaxies. Our parent star, the Sun, belongs to a galaxy called the Milky Way that, according to astronomers, contains between 200 billion and 400 billion stars.
To obtain a universal figure, scientists apply a measurement system similar to that of grains of sand on a long beach; they count the stars of a small volume (the Milky Way) and multiply it according to the dimensions and depth of space. Thus, a figure of 10,000,000,000,000,000,000,000,000 stars is obtained . This is only an estimate, since obviously not all galaxies have identical characteristics, just as in a beach not all areas have the same number of grains of sand.
However, according to recent research, the small, faint stars known as “red dwarfs” are much more prolific than previously thought, tripling the number of total stars from 100,000 trillion to 300,000 trillion.
