The pulsars they are celestial bodies that were only discovered in the last century, creating curiosity in the scientific community for fans of the subject, knowing how they are and how they differ from other stars. We tell you more here.
Learning about pulsars
Point out the RAE, púlsar or pulsar, in Spanish, comes from the union of the two words in English - acronym of puls (ating st) ar-, which means:
“Star that emits very intense radiation at short and regular intervals”,
Its meaning in the Spanish language can be accentuated in two serious and acute ways "In the center of the explosion a pulsar was formed" "Some supernovae have formed a pulsar" and it can also be used for the plural; pulsars and pulsars.
This denomination of "pulsating star", which was adopted, was used is another variety of stars.
Once the orthographic terminology has been clarified, let's move on to the scientific one, defining it, according to Jocelyn Bell (Diario El País, 1999)
“The pulsar, or radio pulsar, is something like a lighthouse. It is an extraordinarily compact body that rotates on itself emitting radio waves. We calculate that its mass is about one thousand quadrillion tons for a size that barely exceeds 10 kilometers in radius. As for its origin, it is the result of a catastrophic and final explosion of a large star with a size ten times larger than our Sun.»
Pulsars are celestial bodies that have a very high intensity magnetic field that will regularly allow them to irradiate.
They are made up of neutrons, which lead them to emit these pulses of "electromagnetic radiation" at a rotation period determined by the speed of the star itself.
All the pulsars that have been found are neutron stars, but does a pulsar have to be a neutron star? No, it turns out that white dwarf stars can also be pulsars.
Characteristics of Pulsars
- They have the ability to rotate on them, up to several hundred times per second.
- They move at speeds of up to 60.000 km/s, to a point on its surface.
- They generate a great speed that allows it to expand from its equator.
- The centrifugal force generated at this high speed, together with its powerful gravitational field due to its enormous density, prevents it from falling apart.
- Stars vary in size, from a few thousand meters to nearly 20 kilometers.
- Neutron stars make good pulsars because they are incredibly dense.
How are pulsars mobilized?
By combining:
- From a fast magnetic field where electrons and protons rotate at very high speeds from its exterior with the rapid movement that was created in its center.
- The solid thickness that is created in the star by other particles that are in the galactic spectrum such as "gas molecules" or "interstellar dust", make the speed of the pulsars even more active and accelerate to extreme resolutions, creating towards their magnetic poles as closed spirals.
A neutron star about twice the mass of our Sun would only be about 20 kilometers across. This means that the magnetic field of a neutron star can be incredibly strong.
It is still unknown to scientists, who were used to observing rotation axes like the Earth's, which is located in the center of the planet and goes from pole to pole. How does the accelerated activity of the pulsar work in its entirety?
The Earth had been studied with theories such as; Kepler's Laws -XNUMXth century, Newton's Law of Gravitation and the Atomic Theory of Democritus, holding:
"Every material particle attracts any other material particle, with a force directly proportional to the product of the masses of both and inversely proportional to the square of the distance that separates them."
Astronomers have observed that the "radiation guns" rotate with the star in circumferences, making the magnetic poles not always point in the same direction.
For this reason, the following question is asked: why do many pulsars present the characteristic that their "magnetic poles" are outside their axis of rotation?
The magnetic jets
It is possible that humans are frequently receiving "magnetic jets". At any moment, when looking at the stellar firmament, if at that precise moment, the star has its "magnetic pole" in the direction of the Earth, it will launch its cannon and then, in micro seconds of its rotation, it will point its "magnetic pole" again. ” and will display another jet and so on cyclically.
Imagine a lighthouse, whose light rotates announcing sailors in the distance. A certain location, this would be these pulses of radiation that we could perceive, with a very exact period and from that point in the sky repeating itself over and over again, each time the jet is oriented towards our planet.
Through special telescopes, pulsars are feasible to analyze for their speed. It is only required that it be oriented to a specific point.
It is important to say that they serve as support for human research activities, because their heart rate is so exact.
Look at this image:
- Magnetic field lines on white
- axis of rotation in green
- Polar radiation jets in blue.
discovery of pulsars
Jocelyn Bell in 1967, first discovered them and since then more than 1,500 of them have been found. While their origin was once a mystery, we now know about pulsars.
These stars that are full of "neutrons" have a permanently accelerated activity. All this makes its "magnetic poles" when emitting its electromagnetic radiation outputs very intense.
«PSR B1919+21, was the first pulsar detected, it had a period of 1,33730113 s»
Through a radio telescope, Jocelyn Bell and Antony Hewish detected these short-lived, constantly repeating radio signals: They thought they might have made contact with an extraterrestrial civilization, so they tentatively named their source LGM - Little Green Men. .
Jocelyn Bell expressed in 1999 to the newspaper El País
“The pulsar, or radio pulsar, is something like a lighthouse. It is an extraordinarily compact body that rotates on itself emitting radio waves. We calculate that its mass is about one thousand quadrillion tons for a size that barely exceeds 10 kilometers in radius. As for its origin, it is the result of a catastrophic and final explosion of a large star with a size ten times larger than our Sun.»
Continuing their investigations, they found other pulsars emitting different frequencies. For this discovery, Anthony Hewish received the 1974 Nobel Prize in Physics. However Jocelyn Bell, who was the first person to hear this frequency, only received an honorary medal.
In 1899, the scientist Nicola Tesla failed to interpret these regular radio waves, which he had found a century earlier during his experiments.
In 1995, Alexander Wolszczan, a scientist at the University of Pennsylvania, worked with radio telescopes and found the "pulsar PSR B1257+12", describing them as a small and ancient celestial object, very dense, that rotates rapidly, and looks like a lighthouse from Earth, there was a planet.
That pulsar is very far from the structure of the earth. On the other hand they also have the hypothesis that near this pulsar there are planets that are around it and that its mass is three times more than that of the Earth:
"These planets in a pulsar allow us to start studying the dynamics of planetary systems, where they come from."
The discovery of the pulsar RX J0806.4-4123 was announced in 2018, unlike the other pulsars found, it emitted infrared radiation, something unique in stars of this type observed to date.
At present, more than 500 pulsars are listed and classified, they have a rotation period from milliseconds to seconds, an average of 0,65 s.
At another time, astronomers in West Asia recorded a brilliant supernova. What later became the most recognized of all pulsars with a rotation period of 0,033 s, is the "Crab Nebula", in 1952 it was named "PSR0531+121".
Then the image of the powerful Crab pulsar.
Radio astronomers Aleksander Wolszczan and Dale A. Frail surprised scientists with their research, because they discovered the pulsar number «PSR B1257+12», whose rotation period is 6,22 milliseconds.
In addition, in their deductions they affirm that there are a number of "extrasolar" planets that have "almost circular orbits at 0,2, 0,36 and 0,47 AU from the central pulsar and with masses of 0,02, 4,3 and 3,9 .XNUMX earth masses respectively”.
What are x-ray pulsars?
These pulsars are peculiar because of the category of radio they emit "X-rays or gamma rays", describing them as if they were radiation guns.
Another great discovery at the interstellar level of scientists was the "X-ray pulsar", they discovered it and it is in a compact star called "Cen X-3 system".
They have also found, in a very surprising way, that these “x-ray” stars belong to a group of binary stars that are composed of “a pulsar and a normally young star of type O or B”.
From its surface and radiation, the first-born star radiates a stellar wind and these are processed by the companion star and generate x-rays.
Last Pulsar Found
Vikram S. Dhillon, an astrophysicist at the University of Sheffield, with his research team and using the Gran Telescopio Canarias (GTC), in the year 2020, discovered the celestial bodies they named "AR Scorpii".
It is a binary system containing a red dwarf star of about half the mass of our Sun and a white dwarf star of about one solar mass.
They are separated by a distance of only 3 times, from the Earth to the Moon and orbit each other every 3.6 hours. This type of binary system is relatively common, but the team noticed that the red dwarf behaved in unusual ways.
The red dwarf pulsates every two minutes. This is too fast for the variation to be due to red dwarf physics.
When the team analyzed the pulsations, they found that it was highly polarized, which is the kind of thing that happens when material is illuminated by high-energy beams. The type of energy beams created by pulsars.