How much energy does a star emit emitted? How many stars are there in the universe

Do you know about the hydrogen bomb? Depending on the mass, stars emit energy per second ...... tens of billions to hundreds of billions of tons of hydrogen bombs

Looking at the night sky from Earth, the universe is a world of stars.

The distribution of stars in the universe is uneven. From the day they were born, they gathered in groups and reflected each other to form binary stars, star clusters, galaxies, ......

Stars are burning planets. In general, stars are relatively large in size and mass. It's just that it's so far away from Earth that the starlight is so faint.

Ancient astronomers believed that the position of a star in the starry sky was fixed, so they named it "star", which means "eternal and unchanging star". But today we know that they are constantly moving at high speeds, such as the sun, which carries the entire solar system around the center of the Milky Way. But other stars are so far away that we can't notice the change in their position.

The ability of stars to emit light can be strong and weak. In astronomy, it is denoted by "luminosity". "Photometricity" refers to the power radiated from the surface of a star in the form of light.

The temperature of the surface of the star can also be high and low. Generally speaking, the lower the temperature of a star's surface, the redder its light is; The higher the temperature, the bluer the light. And the higher the surface temperature, the larger the surface area, and the greater the luminosity.

From the color and luminosity of stars, scientists can extract a lot of useful information.

Historically, astronomer Herzplon and philosopher Russell first proposed the relationship between star classification and color and luminosity, establishing the stellar evolution relationship known as "Her-Roth", revealing the secret of stellar evolution. In the Hera-Gro diagram, from the high temperature and intensity region in the upper left to the low temperature and low light region in the lower right is a narrow stellar dense region, in which our Sun is also included; This sequence is known as the main sequence, and more than 90 stars are concentrated in the main sequence. Above the main sequence region are the giant and supergiant regions; The lower left is the white dwarf region.

Stars are born from interstellar dust in space (as scientists figuratively call "nebulae" or "interstellar clouds").

A star's "youth" is the longest stage of its life, the main sequence phase, which occupies 90 percent of its entire lifespan. During this time, stars glow with almost constant luminosity, illuminating the cosmic space around them.

After this, the star will become turbulent and become a red giant; The red giant will then complete its entire mission in an explosion, ejecting most of its own matter back into space, leaving behind a debris that may be a white dwarf, a neutron star, or even a black hole......

In this way, the star comes from the nebula and returns to the nebula, and completes its glorious life.

The brilliant stars will always be the most beautiful sight in the night sky.

The Sun is an ordinary star, and the energy emitted from its surface is equivalent to 3,700 trillion kilowatts per second. Nuclear fusion is taking place inside it all the time, and when four hydrogen nuclei merge into a helium nucleus, nuclear energy is released. The sun consumes about 600 million tons of hydrogen every second.

Just think about the enormous power of the hydrogen bomb** and you can imagine the energy produced by nuclear fusion inside the star.

The number of stars in the universe is calculated based on the number of stars in the Milky Way. With current technology, we can't see every star in the Milky Way. Visible telescopes can observe stars within a radius of about 5,000 light-years with the Sun as the center, while the radius of the Milky Way is 560,000 light-years, the Sun is about 10,000 light-years from the center of the Milky Way, and the farthest galaxy star is 90,000 light-years from the Sun.

According to current extrapolation, there are about 400 billion stars in the Milky Way, with a plus/minus error of 50%, so the number of stars in the Milky Way is 200 billion 600 billion. There are 100 billion, 200 billion galaxies like the Milky Way. If the number of stars in the Milky Way is calculated at a minimum of 200 billion, the number of stars in the universe is 2 1022 4 1022, that is, 20 trillion 40 trillion billion.

There is no exact number of how many galaxies there are in the universe, some say more than 80 billion, some say more than 100 billion, and some say 1000 200 billion. In 1995, astronomers used the Hubble Space Telescope to observe northern outer space and estimated that there are about 80 billion galaxies in the universe. Three years later, in October 1998, observations were made in outer space in the south, and the number of galaxies in the universe was estimated to be 125 billion.

The reason why the figures for the two observations differ so much, explained by Harry Furguson of the American Space Telescope Science Institute, is due to the fact that the observation distance of outer space in the south is greater than that of outer space in the north. From this, we can know that there are more galaxies in the universe than 125 billion, because the Hubble Space Telescope does not see the edge of the universe.

Astronomers have been thinking about stars and the sun's energy for a long time. The sun, which is the foundation of light and heat on the earth, releases billions of joules of energy into space every second, what kind of fuel makes it burn like this for more than 4 billion years?

At first, some people thought that it was the heat emitted by meteorites and other things around the sun that kept falling into it and burning, but there were too many meteorites needed in this way, and there were not so many meteorites.

Later, some people thought that it was gravity, which caused the sun to contract, and the matter moved towards the center under the gravitational force, converting the gravitational potential energy into kinetic energy, just like when an object on the ground falls, and then the kinetic energy is converted into heat energy. But if you do a careful calculation, the sun's gravitational energy is all converted into heat energy, and it cannot be used to sustain such a long and intense radiation.

While astronomers are struggling to find energy for stars and the sun, physicists are making rapid progress in studying the structure of atomic nuclei and nuclear reactions. At the end of the 30s of this century, physicists theoretically discovered that atomic nuclear reactions can produce enormous amounts of energy. This theory was first used to study the sun's energy sources, and the results surprised astronomers and physicists alike.

Physicists got the first test and support of their theory from "heaven", the energy of the sun can be explained by nuclear energy, and astronomers have solved their own puzzles.

At a high temperature of more than 10 million degrees, 4 hydrogen nuclei can be fused into 1 helium nucleus, and a huge amount of energy is released during the polymerization process, and 1 gram of hydrogen is converted to helium to release 3,000 kilowatt-hours (1 kilowatt-hour is equivalent to 3.6 million joules) of energy, which is equivalent to the heat released by 24 tons of TNT explosives. The most abundant element on a star is hydrogen, and ordinary stars have hundreds of billions of tons of mass, and nuclear reactions can naturally cause stars to radiate intensely for billions of years. Helium nuclei can be synthesized into carbon nuclei, carbon is followed by oxygen, and the substance is gradually converted into heavy elements, and the higher the temperature required for the reaction in the future.

The theory of nuclear reaction was applied to the evolution of stars, and the results of the calculations were completely consistent with the observed data, so that the theory of stellar evolution was developed satisfactorily.

An astronomy team at the Australian National University concluded through calculations that there are 70,000,000,000,000,000,000,000,000 (7 after 22 0, 7 trillion trillions) stars in the universe. Such a huge number could be more than all the grains of sand on all the deserts and beaches on the planet.

The team demarcated a region of the sky and counted the brightness of about 10,000 galaxies in between, to determine the number of stars in them. Such a statistical method avoids the tedious process of counting each star. The number of stars in the entire universe is then obtained by multiplying the number of stars in the entire universe by multiplying the number of stars in the entire sky and this strip-shaped region.

The team used two of the world's most powerful astronomical telescopes for the study, one at the Anglo-Australian Observatory in northern New South Wales and the other in the Canary Islands. At the same time, they say that the number of stars now counted is the number of stars included in the universe that can be seen by modern astronomical telescopes. In fact, there may be more stars in the universe, even infinite.

The universe is so large that even the light on the other side of the universe has not yet reached the earth, so it is not yet possible to measure the detailed data. On the question of whether there is other intelligent life in such a vast universe, the researchers said, "Seven trillions is a huge number. The existence of intelligent life is inevitable.

Trouble, thanks!

Stars, as the name suggests, are stars that are constant or unchanging. It is true that on the surface, the position of the stars in the sky seems to be fixed. The ancients saw that there were several small stars next to Vega forming the shape of a shuttle, so they named it Shuttle Star; He also saw that the Cowherd Star and the two nearby stars looked like a flat star, so he named it the Flat Dan Star.

In ancient times, the shuttle star and the flat dan star still look like the shuttle and the flat dan today. Could it be that these stars are really motionless in the sky? No, by no means.

All stars, like our sun, are in perpetual motion, but they are so far away that their movements are imperceptible to the naked eye. For example, a bird flies in front of its eyes, fleeting; And the plane is much faster than the bird, but we feel that it flies very slowly; The moon moves much faster than an airplane, but when the moon is shining at its head, we often feel that it is still.

In astronomy, a star is a spherical luminous plasma held together by gravity, and the Sun is the closest star to Earth.

Stars are stars in the universe that can heat and shine on their own with the energy produced by nuclear fusion.