The number of stars and planets in the universe. Birth and death of the star
By human standards, our universe is infinite. Its scale is enormous. The number of stars and planets in it is enormous. The human eye distinguishes only three thousand stars in our northern sky, although we often repeat the phrase — All the sky is covered with stars! With the appearance of telescopes, the visible population of the universe began to “grow” rapidly. And it happened every time, as soon as astronomical optics made a step forward. Over time, astronomers began to keep track of entire galaxies, not individual celestial stars, believing that on average each of them contains 100 billion stars!
Three years ago, in 1996, astronomical observatories determined that 50 billion galaxies could be seen from our planet. With the advent of the Hubble Orbital Telescope, which is free from the interference of the Earth's atmosphere, the number of visible galaxies jumped to 125 billion. This telescope has penetrated into such far reaches of the universe that it sees galaxies formed just one billion years after the initial explosion that gave birth to our universe. So now, in order to know the number of stars in the visible universe, we need to attribute to the number 12500000000000 eleven more zeros.
Australian scientists argue that the number of stars tends to infinity and to count them all, of course, it is impossible. Nevertheless, to estimated figure indicative of luminaries in a visible part of the universe astronomers, all the same, managed.
In the process of research using the most powerful tools to measure the brightness of all the galaxies located in one of the sectors of the universe. Based on the data obtained, conclusions were drawn about the number of stars in this sector, and then calculations were made for the entire visible part of the space. According to Australians, the number they get most accurately reflects reality — 70 stallions or, simply put, 7 and 22 zeros. For comparison, all deserts and coasts of our planet contain ten times less sand grains! Many planets (the number of which may well exceed the number of stars) near-distant luminaries may well be populated, but the distance to them is so great that we will never know. At night, some stars look brighter than others. The brightest star in the sky is Sirius. There are stars that shine 100,000 times more intensely than our Sun. Generally speaking, the Sun is an ordinary star, there are stars that are colder, brighter and much larger, for example, the Betelgeuse star. How do the stars form and die? A star similar to our Sun is formed when a cloud of gas begins to contract due to its gravity. In the process of compression, the cloud warms up and begins to glow with a dim red light. When the temperature reaches 10 million degrees Celsius, a vast amount of heat is released. In this state, the star stays 10 billion years. After that, the fuel reserve in the core is exhausted and the star begins to shrink. The combustion of hydrogen fuel takes place outside the core, and the star is blown up and turns into a so-called red giant. The star, discharging the outer layers, forms an expanding outer shell, called the planetary nebula. Core of the former star is a “white dwarf” who cools down and dies out over the next billions of years, becoming a cold “black dwarf”.
Around each of the stars, as a rule, certain groups of planets move, forming together with the star so-called solar systems. What are these systems? Let's consider them on the example of the Earth's solar system.
Find out how many stars in the universe: observations in the sky, the effect of brightness on detection, the number of stars in the Milky Way galaxy, the number of stars for the entire universe.
Looking at the bright lights in the sky, it is very difficult to resist counting. How many stars are there in the sky? Even without the use of technology in the night sky you can see a few thousand stars. And how many of them are there in the Universe? Before we announce this figure, let's find out how many stars are available with various tools.
100% vision will allow you to see the stars of the 6th magnitude. But for completeness of a picture, it is necessary to visit both hemispheres as from everyone the review on new objects opens up. In addition, you need to fit in a few months, as part of the sky is hidden by the sun. So, under ideal conditions and in the absence of a bright moon, you could enjoy 9000 stars.
Take a good pair of binoculars with you and increase the number to 200,000 by adding 9th magnitude objects. The small telescope opens a glance at the 13th size — 15 million stars.
But how many stars exist in the vast expanse of the infinite universe?