In 1967 doctoral student Jocelyn Bell was analyzing data from a new telescope built in Britain.
And she saw signals repeating themselves with regular repetitions, and at that time there was no celestial body that possessed that property, so all that came to her thoughts was that these signals were coming from other alien civilizations.
However, after scrutiny and comparison with other observatories, it was confirmed that these signals are coming from a new type of star currently known as pulsars.
Pulsars are neutron stars that are the corpses of very large stars that have run out of energy and have been violently crushed by gravity.
Ordinary stars like our sun are celestial bodies that we call self-made because they build themselves by themselves and make their energy. Stars begin their lives inside stellar clouds or nebulae, which are dust and gases such as hydrogen resulting from the death of older stars, which we will learn later how they die.
Due to gravity, this stellar dust begins to gather, clump, and swell slowly, and over millions of years, it becomes very large with huge pressure as well so a process called nuclear fusion begins.
Inside the stars, hydrogen atoms begin to fuse, which make up most of the star's mass, and due to the high pressure, they turn into lesser elements such as helium, oxygen, and iron. They also produce very high energy that makes the star stable and resists the gravity that tries to pull it inside.
But this thing doesn't last forever, as this hydrogen will run out after more than a billion years. Gravity begins to overcome the star gradually until it crushes it and explodes from the inside, and the outer layers are scattered in space and it turns into a stellar cloud of dust and gases.
The same thing that started from him, but the heart of the star remains alive, and because of the strong pressure of gravity on this star, the electrons, and protons inside the star's nucleus begin to merge together and become neutrons of moderate charge, and that is why they are called neutron stars.
It is one of the strangest things in the universe, because of its high gravity and high density, it is more likely to be black holes than to be stars.
These neutron stars are made entirely of neutrons tightly packed together so that there is no space between them except on the surface of the star, on which some protons and electrons may exist.
These stars are very small in size and even smaller than our moon, but their mass is like our sun, and they rotate at terrible speeds that reach thousands of revolutions per minute, and because of this high rotational speed, strong and rotating electromagnetic fields are generated around them.
The poles of these fields have deviated from the axis of rotation of the star, and because of their strength, they push the electrons and protons on the surface and release them in the form of radio rays or X-rays in the form of two rays that rotate with the rotation of the star.
If the planet Earth becomes in the path of these rays, we will be able to see this star, and it appears as pulsating and flashing its color whenever this ray passes us, and this method is what made us discover the first mysterious stars, and we are still discovering more.
These pulses are very accurate and sometimes more accurate than the most accurate clocks on Earth, so we can use these pulses to know the time, as well as they are useful for astronautics.
Because of the accuracy of their signals, we can rely on them if we want to travel through the galaxies, because each star sends signals accurately and distinctly, in a way that is unlike any other star, that is, through the signal, we can recognize which star we are looking at.
So far, we know 3000 pulsars inside our galaxy, and by knowing the location of these stars, we can determine our location in space, like the Global Positioning System, but galactic.
The talk, frankly, doesn't end with the characteristics of these wondrous stars, but we will leave the rest to you to search for the subject.