The stars are celestial bodies that are characterized by the luminosity they give off. Their luminosity depends on the amount of energy they emit and the distance they are from our planet.
The stars that exist in space can often appear different colors to us, since their temperatures are different. Those hottest stars are white or blue, and the coolest ones are red or orange.
They can also be classified by their size from dwarfs to supergiants. The stars considered supergiants have radii up to a thousand times greater than that of the Sun. But,How are the stars in the sky? In the following article we will explain it to you.
What are the stars
The stars are accumulations of energy composed of gas and plasma (superheated state of matter) that generate heat, light, ultraviolet rays, X-rays and other forms of energy.
The exact number of stars in space is unknown, although it is an immense number. In the universe it is believed that there are more than 100,000 million galaxies and in each one, more than 100,000 million stars
From planet Earth, up to 3,000 stars can be observed with the naked eye on a clear night. Since ancient times, different peoples have tried to draw the sky thanks to the stars
The stars are consisting mainly of hydrogen, since this is the majority gas that circulates in the form of cosmic dust, forming nebulae. With the passage of time, stars condense until they collapse and it is this decrease in size that causes them to rotate faster and faster and in a spiral.
The accumulation of internal pressure causes their temperature to increase throughout their life and once they have reached 27 million degrees Fahrenheit, they suffer nuclear meltdowns.
How stars are formed and life cycle
- The stars that are just beginning to unfold, we call them protostars. As they grow, they accumulate mass from the surrounding clouds and are called stars in the main sequence. An example of a star in the main sequence is the Sun. These stars live in a state of nuclear fusion emitting energy for millions of years and converting hydrogen into helium.
- After this main sequence period is over, the stars continue their evolution depending on their size and characteristics. In general, the more mass you have, the shorter its existence.
- Once they are near the end of their existence, most of the hydrogen has already been transformed into helium. This formed helium penetrates inside the star, increases its temperature and causes its outer layer to expand. In this phase the star is called red giant.
- Towards the end of this phase, the star is released from the outermost layer and forms a small, dense body called White dwarf.
- These white dwarfs lose their heat over millions of years, until they turn off and their energy production ceases. In this phase (not yet observed for obvious reasons) they are called black dwarfs.
A few stars do not follow this process, but explode as supernovae, producing a neutron star or may go on to form a black hole.
Learn more about what stars are made of in this other Green Ecologist article.
Types of stars
Stars are characterized by the luminosity they give off. Its luminosity depends on the amount of energy they emit and the distance at which they are located from our planet.
The stars that exist in space can appear to us to be of different colors, since their temperatures are different. Those hottest stars are white or blue, and the coolest ones are red or orange.
They can also sort by size from dwarfs to supergiants. The stars considered supergiants have radii up to a thousand times greater than that of the Sun.
The stars are consisting mainly of hydrogen, since this is the majority gas that circulates in the form of cosmic dust, forming nebulae. With the passage of time, the stars condense until they collapse and it is this decrease in size that causes them to rotate faster and faster and in a spiral.
The accumulation of internal pressure causes their temperature to increase throughout their life and once they have reached 27 million degrees Fahrenheit, they suffer nuclear meltdowns.
What shape are the stars
The stars do not have a definite shape, this will vary depending on different factors such as:
- The gravity.
- The turnover rate.
- The proximity to other celestial bodies.
- The stage of their life in which they are.
Next we will talk about two examples to see the difference in the way that stars can have.
- In 2007, an image from a telescope captured the star Altair. This star had a oblong shape due to its high turnover rate.
- In 2008, a group of scientists used a spacecraft to get closer to the Sun and see how round it is. It was seen that although it is usually round, undergoes ripples and bulges as its core rotates and its surface reactions.
If you want to read more articles similar to How are the stars in the sky, we recommend that you enter our category of Curiosities of the Earth and the universe.
