Pulsars were discovered quite by accident in the mid-1960s. This happened during observations using a radio telescope, which was originally designed to study various flickering sources in the uncharted depths of space. What are these space objects?
A group of scientists - Joslyn Bell, Anthony Huis and others - conducted research at the University of Cambridge. These pulses came at intervals of 0.3 seconds, and their frequency was 81.5 MHz. Then astronomers did not yet think about what a pulsar really is and what its nature is. The first thing they noticed was the amazing periodicity of the "messages" they discovered. After all, ordinary flickering occurred in a chaotic mode. Among scientists, there was even an assumption that these signals are evidence of an extraterrestrial civilization trying to reach out to humanity. To designate them, the name LGM was introduced - this English abbreviation meant little green men ("little green men"). Researchers began to make serious attempts to decipher the mysterious "code", and eminent decoders from all over the planet were involved for this. However, their attempts were unsuccessful.
Over the next three years, astronomers discovered 3 more similar sources. And then scientists understood what a pulsar is. It turned out to be another object of the Universe, which has nothing to do with alien civilizations. It was then that pulsars got their name. For their discovery, scientist Anthony Hewish was awarded the Nobel Prize in Physics.
But despite the fact that this discovery happened quite a long time ago, many are still interested in the answer to the question "what is a pulsar." This is not surprising, because not everyone can boast that astronomy was taught at the highest level at his school or university. We answer the question: a pulsar is a neutron star that is formed after a supernova explosion occurs. And so, the constancy of the pulsation, which surprised at the time, can be easily explained - the reason for it is the stability of the rotation of these neutron stars.
In astronomy, pulsars are denoted by a four-digit number. Moreover, the first two digits of the name indicate hours, and the next two - minutes, in which the right ascension of the impulse occurs. And in front of the numbers, two Latin letters are placed, in which the place of discovery is encoded. The very first of all discovered pulsars was named CP 1919 (or "Cambridge Pulsar").
What are pulsars and quasars? We have already figured out that pulsars are the most powerful radio sources, the radiation of which is concentrated in individual pulses of a certain frequency. Quasars are also one of the most interesting objects in the entire universe. They are also extremely bright - exceeding in their power the general power of radiation of galaxies, which are similar to the Milky Way. Quasars have been discovered by astronomers as high redshift objects. According to one of the widespread theories, quasars are galaxies at the initial stage of their development, inside of which there is
One of the most famous such objects in the universe is the pulsar in the Crab Nebula. This discovery shows that the pulsar is one of the most amazing objects in the entire universe.
The explosion of a neutron star in the current Crab Nebula was so powerful that it cannot even fit into the modern theory of astrophysics. In 1054 a.d. e. a new star shone in the sky, which today is called SN 1054. Its explosion was observed even in the daytime, which was evidenced in the historical chronicles of China and the Arab countries. Interestingly, Europe did not notice this explosion - then society was so absorbed in the proceedings between the Pope and his legate, Cardinal Humbert, that not a single scientist of that time recorded this explosion in his works. A few centuries later, a new nebula was discovered at the site of this explosion, later called the Crab Nebula. To its discoverer, William Parsons, for some reason, in its form, it resembled a crab.
And in 1968, the pulsar PSR B0531 + 21 was first discovered, and it was this pulsar that was the first of all that scientists identified with the remnants of a supernova. The source of the pulsation, more strictly speaking, is not the star itself, but the so-called secondary plasma, which is formed in the magnetic field of a star rotating at a frantic speed. The frequency of rotation of the Crab Nebula pulsar is 30 times per second.
But this pulsar is amazing not only for its brightness and frequency. PSR B0531+21 was recently found to emit radioactive rays in a range that exceeds the 100 billion volt mark. This number is millions of times higher than the radiation used in medical equipment, and it is also ten times higher than the value described in the current theory of gamma rays. Martin Schroeder, an American astronomer, puts it this way: “If just two years ago you had asked any astrophysicist the question of whether this kind of radiation could be detected, you would have received a resounding no. There is simply no such theory, in which the fact that we have discovered can fit in. ”
Thanks to the study of the Crab Nebula pulsar, scientists have an idea about the nature of these mysterious objects in space. Now you can more or less clearly imagine what a pulsar is. Their occurrence is explained by the fact that at the final stage of their evolution, some stars explode and flare up with a huge firework - a supernova is born. From ordinary stars, they are distinguished by the power of the flash. In total, about 100 such flares occur in our Galaxy per year. In just a few days, a supernova increases its luminosity by several million times.
Without exception, all nebulae, as well as pulsars, appear at the site of supernova outbursts. However, it is not possible to observe pulsars in all remnants of this type of celestial bodies. This should not confuse astronomers - after all, a pulsar can only be observed if it is located at a certain angle of rotation. In addition, due to their nature, pulsars "live" longer than the nebulae in which they form. Scientists still cannot accurately determine the reasons that cause a cooled and seemingly long-dead star to become a source of powerful radio emission. Despite the abundance of hypotheses, astronomers will have to answer this question in the future.
Probably, those who are wondering what a pulsar is and what is the latest news from astrophysicists about these celestial objects will also be interested in knowing the total number of stars of this kind discovered to date. Today, more than 1,300 pulsars are known to scientists. Moreover, a huge number - about 90% - of these stars pulsate in the range from 0.1 to 1 second. There are even pulsars with even shorter periods - they are called millisecond ones. One of them was discovered by astronomers in 1982 in the constellation Vulpecula. Its rotation period was only 0.00155 seconds. A schematic representation of a pulsar includes an axis of rotation, a magnetic field, and radio waves.
Such short periods of rotation of pulsars served as the main argument in favor of the assumption that, by their nature, they are rotating neutron stars (a pulsar is a synonym for the expression "neutron star"). After all, a celestial body with such a period of rotation must be very dense. Research on these objects is still ongoing. Having learned about what neutron pulsars are, scientists did not stop at previously discovered facts. After all, these stars were truly amazing - their existence could be possible only on the condition that the centrifugal forces that arise as a result of rotation are less than the gravitational forces that bind the substance of the pulsar.
Later it turned out that pulsars with millisecond rotation periods are not the youngest, but, on the contrary, one of the oldest. And pulsars in this category had the weakest magnetic fields.
There is also a type of neutron star called an X-ray pulsar. These are celestial bodies that emit x-rays. They also belong to the category of neutron stars. However, radio pulsars and X-ray emitting stars operate differently and have different properties. The first pulsar of this kind was discovered in 1972 in
When researchers just started to study what pulsars are, they decided that neutron stars have the same nature and density as the nuclei of atoms. Such a conclusion was made, since all pulsars are characterized by hard radiation - exactly the same as that which accompanies nuclear reactions. However, further calculations allowed astronomers to make a different statement. The type of space objects "pulsar" is a celestial body that is similar to giant planets (otherwise called "infrared stars").
- these are cosmic sources of radio, optical, x-ray and / or gamma radiation that come to Earth in the form of periodic bursts (pulses).
Therefore, according to the type of radiation, they are divided into radio pulsars, optical pulsars, X-ray and / or gamma-ray pulsars. The nature of the emission of pulsars has not yet been fully disclosed, models of pulsars and the mechanisms of energy emission by them are studied theoretically. Today, the prevailing opinion is that pulsars are rotating neutron stars with a strong magnetic field.
This happened in 1967. The English radio astronomer E. Hewish and his collaborators discovered short radio pulses coming as if from an empty place in space, repeating stably with a period of at least a second. At first, the results of observations of this phenomenon were kept secret, because. it could be assumed that these radio emission pulses are of artificial origin - perhaps these are signals from some extraterrestrial civilization? But no source of radiation making orbital motion was found, but Hewish's group found 3 more sources of such signals. Thus, the hope for signals from an extraterrestrial civilization disappeared, and in February 1968 a report appeared on the discovery of rapidly variable extraterrestrial radio sources of an unknown nature with a highly stable frequency.
This message caused a real sensation, and in 1974 Hewish received the Nobel Prize for this discovery. This pulsar is called PSR J1921+2153. Currently, about 2 thousand radio pulsars are known, they are usually denoted by the letters PSR and numbers that express their equatorial coordinates.
Astrophysicists have come to the consensus that the radio pulsar is neutron star. It emits narrowly directed streams of radio emission, and as a result of the rotation of a neutron star, the stream enters the field of view of an external observer at regular intervals - this is how pulsar pulses are formed. Most astronomers believe that pulsars are tiny neutron stars with a diameter of several kilometers, rotating with periods of a fraction of a second. They are sometimes even called "star tops". Due to the magnetic field, the radiation of a pulsar is similar to a searchlight beam: when, due to the rotation of a neutron star, the beam hits the antenna of a radio telescope, bursts of radiation are visible. Pulsar signals at different radio frequencies propagate in the interstellar plasma at different speeds. By the mutual delay of the signals, the distance to the pulsar is determined, and their location in the Galaxy is determined. The distribution of pulsars roughly corresponds to the distribution of supernova remnants.
The X-ray pulsar is close binary system, one of the components of which is neutron star, and the second - normal star, resulting in the flow of matter from an ordinary star to a neutron one. neutron stars- these are stars with very small sizes (20-30 km in diameter) and extremely high densities exceeding the density of the atomic nucleus. Astronomers believe that neutron stars are the result of supernova explosions. During a supernova explosion, the core of a normal star rapidly collapses, which then turns into a neutron star. During compression, due to the law of conservation of angular momentum, as well as conservation of the magnetic flux, there is a sharp increase in the speed of rotation and the magnetic field of the star. Thus, it is precisely these two features that are important for an X-ray pulsar: fast rotation speed and extremely high magnetic fields. Matter, hitting the solid surface of a neutron star, is strongly heated and begins to radiate in x-rays. Close relatives of X-ray pulsars are polars and intermediate polars. The difference between pulsars and polars is that a pulsar is a neutron star, while a polar is a white dwarf. Accordingly, they have lower magnetic fields and rotation speed.
In January 1969, the region of the pulsar in the Crab Nebula was surveyed by an optical telescope with photoelectric equipment capable of detecting rapid brightness fluctuations. The existence of an optical object with brightness fluctuations having the same period as the radio pulsar in this nebula was noted. This object turned out to be a 16th-magnitude star at the center of the nebula. She had some kind of illegible spectrum without spectral lines. While investigating the Crab Nebula in 1942, W. Baade pointed to it as a possible stellar supernova remnant, and I.S. Shklovsky in later years suggested that it is a source of relativistic particles and high-energy photons. But these were all just guesses. And here is the star optical pulsar, which has the same period and interpulses as a radio pulsar, and physically it should be a neutron star, the energy consumption of which is sufficient to maintain the glow and all types of radiation from the Crab Nebula. After the discovery of the optical pulsar, searches were also carried out in other supernova remnants, especially in those where radio pulsars had already been found. But only in 1977, using special equipment, Australian astronomers managed to find a pulsation in the optical range of an extremely faint star of the 25th magnitude in the remnant of the supernova Sails X. The third optical pulsar was found in 1982 in the constellation Vulpecula by radio emission. No supernova remnant found.
What is an optical pulsar? The central components of the spectral lines of SS 433 show movements with a period of 13 days and changes in the speed of movement from -73 to +73 km/s. Apparently, there is also a close binary system here, consisting of an optically observable hot supergiant of classes O or B and an X-ray component invisible in optics. The supergiant has a mass of more than ten solar masses, it has swelled up to the limiting boundaries of its own gravitational zone, replenishes with its gas the disk surrounding the X-ray component along the equator of rotation. The plane of the disk is perpendicular to the axis of rotation of the compact object, which is the X-ray component, and does not lie in the orbital plane of the binary system. Therefore, the disk and both gas jets behave like an obliquely rotating top, and the axis of their rotation precesses (describes a cone), making one revolution in 164 days (this is a well-known phenomenon of precession of rotating bodies). The X-ray component that devours disk gas and ejects jets could be a neutron star.
They are among the most powerful cosmic sources of gamma radiation. Astrophysicists are eager to find out how these neutron stars manage to shine so brightly in the gamma range. Before the launch of the Fermi telescope, only about a dozen gamma-ray pulsars were known, while the total number of pulsars was about 1800. Now the new observatory began to discover dozens of gamma-ray pulsars. Scientists hope that her work will provide a wealth of valuable information that will help to better understand the nature of gamma-ray pulsars and other cosmic gamma-ray generators.
In 2012, using the Fermi orbiting gamma-ray telescope, astronomers discovered the fastest gamma-ray pulsar in the constellation Centaurus to date, making one revolution in 2.5 milliseconds and devouring the remains of a companion star the size of Jupiter. ( Gamma radiation (gamma rays, γ rays) - a type of electromagnetic radiation with an extremely short wavelength -< 5·10 −3 нм и, вследствие этого, ярко выраженными корпускулярными и слабо выраженными волновыми свойствами. На картинке гамма-излучение показано фиолетовым цветом.
neutron stars are amazing objects. They have recently been observed with particular interest, because. not only their structure is a mystery, but also their huge density, strong magnetic and gravitational fields. Matter there is in a special state resembling a huge atomic nucleus, and these conditions cannot be reproduced in terrestrial laboratories.
A pulsar is just a huge magnetized top spinning around an axis that does not coincide with the axis of the magnet. If nothing fell on it and it did not emit anything, then its radio emission would have a rotation frequency and we would never hear it on Earth. But the fact is that this top has a colossal mass and a high surface temperature, and the rotating magnetic field creates an electric field of enormous intensity, capable of accelerating protons and electrons almost to the speed of light. Moreover, all these charged particles rushing around the pulsar are trapped in a trap from its colossal magnetic field. And only within a small solid angle near the magnetic axis, they can break free (neutron stars have the strongest magnetic fields in the Universe, reaching 1010-1014 gauss. Compare: the earth's field is 1 gauss, the solar field is 10-50 gauss). It is these streams of charged particles that are the source of that radio emission, according to which pulsars were discovered, which later turned out to be neutron stars. Since the magnetic axis of a neutron star does not necessarily coincide with the axis of its rotation, when the star rotates, a stream of radio waves propagates in space like a beam of a flashing beacon - cutting through the surrounding darkness only for a moment.
A pulsar can be seen at the center of the M82 galaxy (pink)
Explore pulsars and neutron stars Universe: description and characteristics with photo and video, structure, rotation, density, composition, mass, temperature, search.
Pulsars are spherical compact objects, the dimensions of which do not go beyond the boundaries of a large city. Surprisingly, with such a volume, they surpass the solar one in massiveness. They are used to study extreme states of matter, detect planets outside our system, and measure cosmic distances. In addition, they helped find gravitational waves that indicate energetic events, such as supermassive collisions. First discovered in 1967.
If you look out for a pulsar in the sky, it seems like an ordinary twinkling star, following a certain rhythm. In fact, their light does not flicker or pulse, and they do not appear as stars.
The pulsar produces two persistent narrow beams of light in opposite directions. The flickering effect is created due to the fact that they rotate (lighthouse principle). At this point, the beam hits the Earth and then turns again. Why is this happening? The fact is that the light beam of a pulsar usually does not coincide with its axis of rotation.
If the blinking is created by rotation, then the speed of the pulses reflects that at which the pulsar rotates. A total of 2,000 pulsars have been found, most of which make one revolution per second. But there are about 200 objects that manage to make a hundred revolutions in the same time. The fastest ones are called milliseconds because their number of revolutions per second is equal to 700.
Pulsars cannot be considered stars, at least "alive". They are more like neutron stars that form after a massive star runs out of fuel and collapses. As a result, a strong explosion is created - a supernova, and the remaining dense material is transformed into a neutron star.
The diameter of pulsars in the universe reaches 20-24 km, and the mass is twice that of the sun. To give you an idea, a piece of such an object the size of a sugar cube would weigh 1 billion tons. That is, something weighing Everest is placed in your hand! True, there is an even denser object - a black hole. The most massive reaches 2.04 solar masses.
Pulsars have strong magnetic fields that are 100 million to 1 quadrillion times stronger than Earth's. In order for a neutron star to start emitting light like a pulsar, it must have the right ratio of magnetic field strength and rotational speed. It happens that a beam of radio waves may not pass through the field of view of a ground-based telescope and remain invisible.
radio pulsars
Astrophysicist Anton Biryukov on the physics of neutron stars, slowing down rotation and the discovery of gravitational waves:
The slowness for a pulsar is one rotation per second. The fastest accelerate to hundreds of revolutions per second and are called millisecond. The rotation process occurs because the stars from which they formed also rotated. But to get to this speed, you need an additional source.
Researchers believe that millisecond pulsars were formed by stealing energy from a neighbor. You can notice the presence of foreign matter, which increases the speed of rotation. And this is not good for the affected companion, which one day may be completely absorbed by the pulsar. Such systems are called black widows (after the dangerous species of spider).
Pulsars are capable of emitting light in several wavelengths (from radio to gamma rays). But how do they do it? Scientists have yet to find a definitive answer. It is believed that a separate mechanism is responsible for each wavelength. Beacon-like beams are made up of radio waves. They are bright and narrow and resemble coherent light, where particles form a focused beam.
The faster the rotation, the weaker the magnetic field. But the speed of rotation is enough for them to emit the same bright rays as the slow ones.
During rotation, the magnetic field creates an electric field, which is able to bring charged particles into a mobile state (electric current). The area above the surface where the magnetic field dominates is called the magnetosphere. Here, charged particles are accelerated to incredibly high speeds due to the strong electric field. With each acceleration, they emit light. It is displayed in the optical and X-ray range.
What about gamma rays? Research suggests that their source must be sought elsewhere near the pulsar. And they will resemble a fan.
Radio telescopes remain the main method for searching for pulsars in space. They are small and weak compared to other objects, so you have to scan the entire sky and gradually these objects fall into the lens. Most of it was found using the Parkes Observatory in Australia. A lot of new data will be available from the Square Kilometer Antenna Array (SKA) launching in 2018.
In 2008, the GLAST telescope was launched, which found 2050 gamma-ray pulsars, of which 93 were millisecond. This telescope is incredibly useful because it scans the entire sky, while others only highlight small areas along the plane.
Finding different wavelengths can be problematic. The fact is that radio waves are incredibly powerful, but they may simply not fall into the telescope lens. But gamma rays spread over most of the sky, but are inferior in brightness.
Scientists now know about the existence of 2,300 pulsars found through radio waves and 160 through gamma rays. There are also 240 millisecond pulsars, of which 60 produce gamma rays.
Pulsars are not just amazing space objects, but also useful tools. The emitted light can tell a lot about internal processes. That is, researchers are able to understand the physics of neutron stars. In these objects, the pressure is so high that the behavior of matter is different from the usual. The strange filling of neutron stars is called "nuclear paste".
Pulsars bring many benefits due to the accuracy of their pulses. Scientists know specific objects and perceive them as cosmic clocks. This is how speculation about the presence of other planets began to appear. In fact, the first exoplanet found orbited a pulsar.
Do not forget that pulsars continue to move during the “blinking”, which means that you can use them to measure cosmic distances. They were also involved in testing Einstein's theory of relativity, like moments with gravity. But the regularity of the pulsation can be disturbed by gravitational waves. This was noticed in February 2016.
Gradually, all pulsars slow down. The radiation is powered by a magnetic field created by rotation. As a result, it also loses its power and stops sending beams. Scientists have deduced a special feature where you can still find gamma rays in front of radio waves. As soon as the pulsar falls below, it is written off in the graveyard of pulsars.
If the pulsar was formed from the remnants of a supernova, then it has a huge energy reserve and a fast rotation speed. Examples include the young object PSR B0531+21. In this phase, it can stay for several hundred thousand years, after which it will begin to lose speed. Middle-aged pulsars make up the majority of the population and produce only radio waves.
However, a pulsar can extend its life if there is a companion nearby. Then it will pull out its material and increase the speed of rotation. Such changes can occur at any time, so the pulsar is able to revive. Such a contact is called a low-mass X-ray binary system. The oldest pulsars are millisecond. Some are billions of years old.
neutron stars- rather mysterious objects exceeding the solar mass by 1.4 times. They are born after the explosion of larger stars. Let's get to know these formations closer.
When a star explodes, 4-8 times more massive than the Sun, a core with a high density remains, which continues to collapse. Gravity pushes so hard on the material that it causes protons and electrons to coalesce to appear as neutrons. This is how a high-density neutron star is born.
These massive objects are capable of reaching a diameter of only 20 km. To give you an idea of density, just one spoonful of neutron star material would weigh a billion tons. The gravity on such an object is 2 billion times stronger than Earth's, and the power is enough for gravitational lensing, allowing scientists to view the back of the star.
The shock from the explosion leaves an impulse that causes the neutron star to rotate, reaching several revolutions per second. Although they can accelerate up to 43,000 times per minute.
Boundary layers near compact objects
Astrophysicist Valery Suleimanov on the origin of accretion disks, stellar wind and matter around neutron stars:
The interior of neutron stars
Astrophysicist Sergei Popov on extreme states of matter, the composition of neutron stars and ways to study the depths:
When a neutron star is part of a binary system where a supernova exploded, the picture looks even more impressive. If the second star was inferior in massiveness to the Sun, then it pulls the mass of the companion into the “Roche petal”. This is a spherical cloud of matter that makes revolutions around a neutron star. If the satellite was 10 times larger than the solar mass, then the mass transfer is also adjusted, but not as stable. The material flows along the magnetic poles, heats up and X-ray pulsations are created.
By 2010, 1800 pulsars had been found using radio detection and 70 through gamma rays. Some specimens even noticed planets.
In some representatives of neutron stars, jets of material flow almost at the speed of light. When they fly past us, they flash like a beacon. Because of this, they are called pulsars.
Supernova remnant Korma-A, at the center of which is a neutron star
Neutron stars are the remnants of massive stars that have reached the end of their evolutionary path in time and space.
These interesting objects are born from once massive giants that are four to eight times the size of our Sun. It happens in a supernova explosion.
After such an explosion, the outer layers are ejected into space, the core remains, but it is no longer able to support nuclear fusion. Without external pressure from the overlying layers, it collapses and shrinks catastrophically.
Despite their small diameter - about 20 km, neutron stars boast 1.5 times the mass of our Sun. Thus, they are incredibly dense.
A small spoonful of star matter on Earth would weigh about a hundred million tons. In it, protons and electrons are combined into neutrons - this process is called neutronization.
Their composition is unknown; it is assumed that they may consist of a superfluid neutron liquid. They have an extremely strong gravitational pull, much stronger than that of the Earth and even the Sun. This gravitational force is especially impressive because it has a small size.
All of them rotate around an axis. During compression, the angular momentum of rotation is preserved, and due to a decrease in size, the rotation speed increases.
Due to the huge speed of rotation, the outer surface, which is a solid “crust”, periodically cracks and “starquakes” occur, which slow down the rotation speed and dump “excess” energy into space.
The overwhelming pressure that exists in the core may be similar to that which existed at the time of the big bang, but unfortunately it cannot be simulated on Earth. Therefore, these objects are ideal natural laboratories where we can observe energies inaccessible on Earth.
Radio pulsars were discovered in late 1967 by graduate student Jocelyn Bell Burnell as radio sources that pulsate at a constant frequency.
The radiation emitted by the star is visible as a pulsating radiation source or pulsar.
Schematic representation of the rotation of a neutron star
Radio pulsars (or simply a pulsar) are spinning neutron stars whose jets of particles move at nearly the speed of light, like a spinning beacon beam.
After continuous rotation, for several million years, pulsars lose their energy and become normal neutron stars. Only about 1,000 pulsars are known today, although there may be hundreds of them in the galaxy.
Radio pulsar in the Crab Nebula
Some neutron stars emit X-rays. The famous Crab Nebula is a good example of such an object, formed during a supernova explosion. This supernova explosion was observed in 1054 AD.
Pulsar wind, Chandra video
A radio pulsar in the Crab Nebula photographed by the Hubble Space Telescope through a 547nm filter (green light) from August 7, 2000 to April 17, 2001.
Neutron stars have a magnetic field millions of times stronger than the strongest magnetic field produced on Earth. They are also known as magnetars.
Planets near neutron stars
So far, four are known to have planets. When it is in a binary system, it is possible to measure its mass. Of these binary systems in the radio or X-ray range, the measured masses of neutron stars were about 1.4 times the mass of the Sun.
A completely different type of pulsar is seen in some X-ray binaries. In these cases, a neutron star and an ordinary one form a binary system. A strong gravitational field pulls material from an ordinary star. Material falling on it during the accretion process heats up so much that it produces X-rays. Pulsed X-rays are visible when hot spots on a spinning pulsar pass through the line of sight from Earth.
For binary systems containing an unknown object, this information helps to distinguish whether it is a neutron star, or, for example, a black hole, because black holes are much more massive.
Astronomers have studied the sky since time immemorial. However, only with a significant leap in the development of technology, scientists were able to discover objects that previous generations of astronomers did not even have in their imagination. Some of them are quasars and pulsars.
Despite the enormous distances to these objects, scientists managed to study some of their properties. But despite this, they still hide a lot of unsolved secrets.
What are pulsars and quasars
The pulsar, as it turned out, is a neutron star. Its pioneers were E. Huish and his graduate student D. Bell. They were able to detect pulses, which are streams of radiation of a narrow direction, which become visible after certain time intervals, since this effect occurs due to the rotation of neutron stars.
A significant compaction of the star's magnetic field and its very density occurs during its compression. It can be reduced to a size of several tens of kilometers, and at such moments the rotation occurs at an incredibly high speed. This speed in some cases reaches thousandths of a second. This is where electromagnetic radiation waves come from.
Quasars and pulsars can be called the most unusual and mysterious discoveries of astronomy. The surface of a neutron star (pulsar) has less pressure than its center, for this reason neutrons decay into electrons and protons. Electrons are accelerated to incredible speeds due to the presence of a powerful magnetic field. Sometimes this speed reaches the speed of light, resulting in the ejection of electrons from the magnetic poles of the star. Two narrow beams of electromagnetic waves - this is exactly what the movement of charged particles looks like. That is, electrons emit radiation in the direction of their direction.
Continuing the enumeration of unusual phenomena associated with neutron stars, their outer layer should be noted. In this sphere, there are spaces in which the core cannot be destroyed due to insufficient density of the substance. The consequence of this is that the densest crust is covered by the formation of a crystalline structure. As a result, stress accumulates and at a certain moment this dense surface begins to crack. Scientists call this phenomenon "starquake".
Pulsars and quasars remain completely unexplored. But if amazing studies have told us about pulsars or the so-called. neutron stars have a lot of new things, quasars keep astronomers in the suspense of the unknown.
The world first learned about quasars in 1960. The discovery said that these are objects with small angular dimensions, which are characterized by high luminosity, and by class they belong to extragalactic objects. Because they have a rather small angular size, for many years it was thought that they were just stars.
The exact number of discovered quasars is unknown, but in 2005, studies were conducted in which there were 195,000 quasars. So far, nothing available to explain about them is known. There are many assumptions, but none of them has any evidence.
Astronomers have found out only that for a time interval of less than 24 hours, their brightness marks sufficient variability. According to these data, one can note their relatively small size of the emission region, which is comparable to the size of the solar system. Found quasars exist at a distance of up to 10 billion light years. It was possible to see them because of their highest level of luminosity.
The closest such object to our planet is located approximately at around 2 billion light years. Perhaps future research and the latest technologies used in them will provide mankind with new knowledge about the white spots of outer space.
