PRESENTATION ABOUT STARS

Presentation

About the Stars

Questions: Did you used to see the stars as a child? Have you heard any stories about the stars? or the constellations? Have you noticed the sky these days compared to when you were younger?

Star Evolution

Stars are celestial bodies that are constantly changing. This phenomenon is characterized as stellar evolution, which consists of observing the transformations of stars during their life cycle. These evolutions can take billions of years.

Birth of a star

The first stage of star evolution is the birth of a star. They are born in a cloud that contains molecules of gas and dust. The action of gravity is responsible for the junction of the gases with the dust, causing the loss of the densest parts. Then, a piece of this gas-dust junction gains density and heat, becoming a kind of disk.

A star disk

After millions of years, this disk reaches a temperature and density so high that hydrogen gases turn into helium. This step marks the beginning and the appearance of the star. Nuclear mergers do not cease and are responsible for the structural change of stars.With the core quite heated, they increase in size and become reddish luminosity, being known as the red giant.

Explosion of a star

Then, the size will be decisive for the fate of these stars. For those with a mass equal to that of the Sun, the end of the cycle is the transformation into a white dwarf star. The end of the life cycle can have two different outcomes: the thermonuclear explosion of the star can cause the appearance of a black hole or originate neutron stars.

Stories and Astronomy

Ancient astronomers created regions that were basically drawings formed by connecting the stars, as if in a game of connecting the dots. These drawings could be used as references and were called constellations.Many constellations were used to tell stories about a diverse subject, but the main one was mythology.

International Astronomical Union (IAU)

In the 20th century, the need arose to create a universal system of constellations, so that everyone recognized the sky in the same way. In 1929, the International Astronomical Union (IAU) divided the sky into 88 regions, which would be identified with the help of a draw. Most of the constellations chosen by them were associated with Greek mythology.

Important note

It is important to understand that the constellations are not real objects, they are just patterns that the stars form in the sky, observed here on Earth. These stars that we observe close to each other and that show us a drawing, are often extremely distant from each other and have no connections with each other.

Seasons with the stars

We can use the constellations as a reference to mark the seasons. Orion, for example, if observed close to the east in the early evening, will indicate that we are in the summer of the southern hemisphere, or winter of the northern hemisphere. The constellation that is on the opposite side of Orion in the sky is Scorpio. By being on the opposite side, considering the southern hemisphere, when Scorpio appears east in the sky in the early evening, you can say that it is in the opposite season, winter, or summer in the northern hemisphere.

Heaven on the day of your birth

There is a website where you can search how yours was on the day of your birth, or even an important day for you. It doesn't necessarily have to be a holiday, you can search the day you want. It does the sky simulation on the chosen day, then you can buy or order a photo to print at home.

https://www.mapadomeuceu.com.br/produto/mapa-das-estrelas/

There is also a website where we can see what happened in space, on the day and month of our anniversary. NASA makes this information available in its system

NASA

https://www.nasa.gov/content/goddard/what-did-hubble-see-on-your-birthday.

Current and former times

If we compare the sky in current times with the old days, in big cities, we will realize that with pollution and the visibility of the stars we lose, we can see only the moon and the sun, without the telescope. With the telescope we have better visibility of them.

¡thanks!