Many times we look at the sky and see the stars in the sky scattered throughout space. However, there are people who do not know very well what are the stars Scientifically, we define a star as a large sphere of dust and gas found in our universe that shines on its own. That is, it's a large, incandescent star that gives off its own light and appears in the sky as a luminous point.
In this article we are going to tell you what stars are, what their main characteristics are and how they are formed.
What are the stars
There is room for a celestial body known to be incandescent and have its own luminosity. It not only emits light but also heat. Due to the large number of stars, the total number that exists in the universe is not known exactly. Since we also do not know the entire extent of the universe as a whole, We cannot know exactly how many stars there are. However, some of the most experienced scientists have identified many of them and made some estimates of the total abundance.
To get an idea of the total number that may exist in the sky, we will use a more sophisticated telescope. With this type of telescope, we can reach Observe more than 3.000 billion stars in the visible sky. This makes the total number of stars quite far from exact.
The star most abundant on our planet is the only one that forms the solar system. It's the sun. It guarantees life on our planet as we know it. Other stars closest to our planet belong to the solar system. Alpha Centauri, which is located at a distance of 4.37 light years. If you want to know more about other nearby stars, we recommend reading about the stars bigger than the sun and about double stars.
Characteristics of the stars
Once we know what stars are, let's learn about their characteristics. They are celestial bodies composed primarily of hydrogen and helium. Normally They usually have ages ranging from 1 to 10 billion years.. Given their formation and their characteristics, they are not bodies that have a uniform distribution in the universe. Normally all of these stars tend to cluster together to form galaxies. In these galaxies they contain dust and gas and it is what makes up all this grouping of stars.
There are some that are isolated and others that are arranged very closely due to the pull of gravity. These stars that are together with each other come to form true systems. There are some stars that are binary. This means that a star is composed of two smaller stars. Since there are many star clusters, we also see that multiple systems exist. These multiple systems consist of formations of three or more stars. These systems can be triple, quadruple, quintuple, etc. If you want to learn more about the different configurations, you can consult our article on and also on types of stars.
Another characteristic is that they emit radiation as a result of a process called nuclear fusion. This process occurs when two hydrogen atoms join together to form a new, heavier atomic nucleus. This nuclear reaction would be of great interest to humans and their energy formation. However, large amounts of energy and temperature are required for their formation. Given the production of this process, electromagnetic radiation is produced and conducive to emitting light and producing energy.
The color depends on the temperature and the outer layers. The colder the stars, the redder they appear. On the other hand, hotter stars give off a blue color. Once we know what stars are, we must know that they have a beginning and an end. The matter that makes them up transforms into something else once they have fulfilled their function. As we mentioned before, stars are typically between 1 and 10 billion years old. If you are interested in learning more about the colors of stars, you can read our article on What color are the stars and about the Shooting Stars and its best dates.
Training
Many people don't know what stars are, but even fewer know how they form and how they are destroyed. Often, people talk about the birth of a star, if it were a living being. Star formation is a process that can be summarized simply. Stars form after the existence of a cloud of dust and gas within a galaxy. Clouds of dust and gas are nebulae floating in the universe. If there is any type of turbulence within a nebula, either due to a collision with another nebula or some other event, gas and dust collapse under their own gravitational pull.
To put it more simply, for a star to form, hydrogen, helium, and stardust must begin to attract each other. As the nebula rotates, it becomes smaller, and these elements attract each other. As this happens, the center of the nebula becomes with a higher density and a higher temperatureThis is when they begin to shine. During the collapse process, the nebula acquires a hot core and collects dust and gas from its surroundings. Occasionally, some of the existing material may form planets, asteroids, and other celestial bodies. However, if all the matter in the center reaches temperatures high enough for nuclear fusion to occur and energy to be released, a star will be born. If you'd like to learn more about this process, you can visit our article on How do stars form and if you are interested in the showers of stars that occur in the sky, here you will find interesting information.
Scientists have estimated that the temperature required for a star can be born around 15 million degrees Celsius. Stars that are young and have recently formed are called protostars.
What are stars: evolution
Finally, we already know what the stars are and we are going to know what their evolution is. The life cycle of stars is known as stellar evolution. It has the following stages:
- Protostars: it is the one in which its birth begins.
- Star in main sequence: this is its stage of maturity and stability.
- It depletes the hydrogen at its center: Here nuclear fusion will cease, and the core will begin to collapse in on itself and become hotter. Evolution can take different paths depending on the star's mass. The larger and more massive the star, the shorter its lifetime.
I hope that with this information you can learn more about what stars are and their characteristics.