A beautiful space spinning top could one day destroy the Earth with deadly rays, scientists report.
Unlike the Star Wars Death Star, which needed to get close to a planet to blow it up, this blazing spiral is capable of burning worlds thousands of light-years away, much like the Death Galaxy already described on our website.
"I loved this spiral because of its beauty, but now looking at it, I can't help but feel like I'm looking down the barrel of a gun," said researcher Peter Tuthill, an astronomer at the University of Sydney.
At the heart of this fiery cosmic top are two hot, bright stars circling each other. In such mutual rotation, flashes of flowing gas escape from the surface of stars and collide in the intermediate space, gradually intertwining and twisting by the orbits of stars into rotating spirals.
A sequence of 11 images, combined and colorized, shows a spinning top formed by the double star Wolf-Raet 104. The images were taken in near-infrared by the Keck telescope. Peter Tuthill, University of Sydney.
Short circuit
Yula, called WR 104, was discovered eight years ago in the constellation Sagittarius. It circles "every eight months, with the precision of a cosmic chronometer," says Tuthill.
Both heavy stars in WR 104 will one day explode as a supernova. However, one of the two stars is a highly unstable Wolf-Rae-type star, which is in the last known phase of the life of heavy stars before going supernova.
"Astronomers think Wolf-Rae stars are ticking bombs," explains Tuthill. "This star's 'fuse' is almost - astronomically speaking - blown, and it could explode at any time within the next few hundred thousand years."
When Wolf Rae goes supernova, it “could throw a huge gamma ray in our direction,” says Tuthill. “And if such a gamma ray explosion occurs, we would really not want the Earth to get in its way.”
Since the initial blast wave will move at the speed of light, nothing can warn of its approach.
In the line of fire
Gamma ray bursts are the most powerful explosions known to us in the universe. In times ranging from a few milliseconds to a minute or more, they can release as much energy as our Sun in its entire 10 billion years of existence.
But the most eerie thing about this yule is that we see it as a near-perfect spiral, according to the latest images from the Keck telescope in Hawaii. “Thus, we can only see a binary system when we are practically on its axis,” explains Tuthill.
To our greatest regret, the emission of gamma rays occurs directly along the axis of the system. In fact, if a gamma ray release ever occurs, our planet could be right in the line of fire.
"It's the first object we know of that can fire gamma rays at us," says astrophysicist Adrian Melott of the University of Kansas at Laurence, who was not involved in the study. "And the distance to the system is frighteningly close."
Yula is about 8,000 light-years from Earth, about a quarter of the way to the center of the Milky Way galaxy. While that seems like a decent distance, "earlier studies have shown that a gamma-ray burst could be devastating to life on Earth - if we're not lucky enough to get in its way - and at that distance," says Tuthill.
Possible Scenario
Although the spinning wheel cannot blow the Earth to pieces like the Death Star and Star Wars - at least not from a distance of 8000 light years - it can lead to mass destruction and even the complete extinction of life, in forms known to us, on our planet.
Gamma rays can't penetrate Earth's atmosphere deep enough to burn the soil, but they can chemically alter the stratosphere. Melot calculated that if the WR 104 fired a burst of about 10 seconds at us, the gamma rays would deprive us of 25 percent of the ozone layer that protects us from harmful ultraviolet rays. In comparison, the human-induced thinning of the ozone layer, which created "ozone holes" over the polar regions, reduced the ozone layer by only 3-4 percent.
“Things will be very bad,” says Melot. Everything will start to die. The food chain can collapse in the oceans, there can be an agricultural crisis and famine.”
The release of gamma rays can also lead to sun-dark fog and acid rain. However, the distance of 8,000 years is “too long for the dimming to be noticeable,” Melot said. - I would say, in general, there will be less sunlight by 1-2 percent. The climate may get a little colder, but it should not reach a catastrophic ice age.”
The danger of cosmic rays
What is unknown about gamma rays is how many particles they spew out as cosmic rays.
“Typically, gamma ray bursts occur so far away from us that the magnetic fields of the universe pull off any cosmic rays that we might observe, but if the gamma ray burst occurs relatively close, all high-energy particles will rush through the magnetic field of the galaxy and hit us,” Melot says. “Their energy will be so high that they will arrive almost simultaneously with the light flux.”
“That part of the Earth, which turns out to be facing the flow of gamma rays, will experience something similar to that located not far from a nuclear explosion; all organisms can get radiation sickness, Melot adds. Moreover, cosmic rays can exacerbate the effect of gamma rays on the atmosphere. But we simply don't know how many cosmic rays gamma rays emanate, so we can't assess the severity of the danger."
It is also not clear how wide the flow of energy released by the burst of gamma rays will be. But in any case, the cone of destruction emanating from the spinning top will reach several hundred square light-years before it reaches the Earth, according to Melot's calculations. Tuthill, on the other hand, states that "no one can fly a spaceship far enough not to hit the beam if it actually fires in our direction."
Fictional "Death Star" from "Star Wars"
Don't worry
Nevertheless, Tunhill thinks that the top may be quite safe for us.
“There are too many uncertainties,” he explains. “The radiation can pass by without causing us any harm if we are not exactly on the axis, and besides, no one is completely sure that stars like WR 104 are able to cause such a powerful burst of gamma radiation.
Future research should focus on whether WR 104 is indeed aimed at Earth and how supernova birth results in gamma ray bursts.
Melot and others have also speculated that gamma ray showers could have caused a mass extinction of species on Earth. But when it comes to whether the whirligig poses a real threat to us, Melot notes: "I'd rather be worried about global warming."
>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
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.
What is a pulsar?
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:
Why do pulsars rotate?
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.
Search for pulsars
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.
Use of pulsars
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.
Pulsar graveyards
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 line 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
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.
Types of neutron stars
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.
When X-ray pulsars take material from more massive neighbors, it contacts the magnetic field and creates powerful beams observed in the radio, X-ray, gamma and optical spectrum. Since the source is located in a companion, they are called accretionary pulsars.
Spinning pulsars in the sky follow the rotation of stars because high-energy electrons interact with the pulsar's magnetic field above the poles. As matter inside the pulsar's magnetosphere accelerates, this causes it to produce gamma rays. The return of energy slows down the rotation.
Back in 1932, the young Soviet theoretical physicist Lev Davidovich Landau (1908-1968) concluded that superdense neutron stars exist in the Universe. Imagine that a star the size of our Sun would shrink to a size of several tens of kilometers, and its matter would turn into neutrons - this is a neutron star.
As theoretical calculations show, stars with a core mass more than 1.2 times the solar mass explode after exhausting the nuclear fuel and shed their outer shells with great speed. And the inner layers of the exploded star, which are no longer hindered by gas pressure, fall to the center under the influence of gravitational forces. In a few seconds, the volume of the star decreases by 1015 times! As a result of the monstrous gravitational compression, free electrons are pressed into the nuclei of atoms, as it were. They combine with protons and neutralize their charge to form neutrons. Deprived of an electric charge, neutrons under the load of the overlying layers begin to quickly approach each other. But the pressure of the degenerate neutron gas stops further compression. A neutron star appears, almost entirely composed of neutrons. Its dimensions are about 20 km, and the density in the depths reaches 1 billion tons/cm3, that is, it is close to the density of the atomic nucleus.
So, a neutron star is like a giant nucleus of an atom, supersaturated with neutrons. Only unlike the atomic nucleus, neutrons are held not by intranuclear forces, but by gravitational ones. According to calculations, such a star cools rapidly, and within a few thousand years that have elapsed after its formation, the temperature of its surface should drop to 1 million K, which is also confirmed by measurements made in space. Of course, this temperature itself is still very high (170 times higher than the surface temperature of the Sun), but since a neutron star is composed of extremely dense matter, its melting temperature is much more than 1 million K. As a result, the surface of neutron stars must be ... solid ! Although such stars have a hot, but solid crust, the strength of which is many times greater than the strength of steel.
The force of gravity on the surface of a neutron star is so great that if a person still managed to reach the surface of an unusual star, he would be crushed by its monstrous attraction to the thickness of the trace that remains on an envelope from a postal item.
In the summer of 1967, a graduate student at the University of Cambridge (England), Jocelina Bell, received very strange radio signals. They came in short pulses exactly every 1.33730113 seconds. The exceptionally high accuracy of the radio pulses led me to think: are these signals being sent by representatives of civilization to the mind?
However, over the next few years, many similar objects with fast pulsating radio emission were found in the sky. They were called pulsars, that is, pulsating stars.
When radio telescopes were aimed at the Crab Nebula, a pulsar with a period of 0.033 seconds was also found at its center. With the development of extra-atmospheric observations, it was found that it also emits X-ray pulses, and X-ray radiation is the main one and is several times stronger than all other radiations.
Soon, researchers realized that the reason for the strict periodicity of pulsars is the rapid rotation of some special stars. But such short periods of pulsations, which range from 1.6 milliseconds to 5 seconds, can be explained by the rapid rotation of only very small and very dense stars (centrifugal forces will inevitably tear a large star apart!). And if so, then pulsars are nothing but neutron stars!
But why do neutron stars spin so fast? Recall: an exotic star is born as a result of a strong compression of a huge luminary. Therefore, in accordance with the principle of conservation of angular momentum, the speed of rotation of the star must increase sharply, and the rotation period must decrease. In addition, the neutron star is still strongly magnetized. The strength of the magnetic field on the surface is a trillion (1012) times greater than the strength of the Earth's magnetic field! A powerful magnetic field is also the result of a strong compression of the star - a decrease in its surface and a thickening of magnetic field lines. However, the true source of activity of pulsars (neutron stars) is not the magnetic field itself, ci is the rotational energy of the star. And losing energy to electromagnetic and corpuscular radiation, pulsars gradually slow down their rotation.
If radio pulsars are single neutron stars, then X-ray pulsars are components of binary systems. Since the gravitational force on the surface of a neutron star is billions of heavens than on the Sun, it "draws on itself" the gas of a neighboring (ordinary) star. Particles of gas are pushed onto a neutron star at high speed, heated up when they hit its surface and emit X-rays. A neutron star can become a source of X-rays even if it "wanders" and a cloud of interstellar gas.
What is the mechanism of neutron star pulsation made up of? It should not be thought that the star is simply pulsating. The case is quite different. As already mentioned, a pulsar is a rapidly rotating neutron star. On its surface, apparently, there is an active region in the form of a "hot spot", which emits a narrow, strictly directed beam of radio waves. And at that moment, when that beam is directed towards the earthly observer, the latter will mark the radiation pulse. In other words, a neutron star is like a radio beacon, and the period of its pulsation is determined by the period of rotation of this "beacon". Based on such a model, one can understand why, in a number of cases, at the site of a supernova explosion, where the pulsar must certainly be, it was not detected. Only those pulsars are observed whose radiation is successfully oriented with respect to the Earth.
A neutron star is a very rapidly rotating body left after an explosion. With a diameter of 20 kilometers, this body has a mass comparable to that of the sun; one gram of a neutron star would weigh more than 500 million tons on earth! Such a huge density arises from the indentation of electrons into nuclei, from which they combine with protons and form neutrons. In fact, neutron stars are very similar in properties, including density and composition, to atomic nuclei. But there is a significant difference: in nuclei, nucleons are attracted by strong interaction, and in stars, by force
What is
In order to understand what these mysterious objects are, we strongly recommend that you refer to the speeches of Sergei Borisovich Popov Sergei Borisovich Popov Astrophysicist and popularizer of science, Doctor of Physical and Mathematical Sciences, Leading Researcher of the State Astronomical Institute named after I.I. PC. Sternberg. Laureate of the Dynasty Foundation (2015). Laureate of the state award "For fidelity to science" as the best popularizer of 2015
Composition of neutron stars
The composition of these objects (for obvious reasons) has been studied so far only in theory and mathematical calculations. However, much is already known. As the name implies, they consist mainly of densely packed neutrons.
The atmosphere of a neutron star is only a few centimeters thick, but all of its thermal radiation is concentrated in it. Behind the atmosphere is a crust composed of densely packed ions and electrons. In the middle is the nucleus, which is made up of neutrons. Closer to the center, the maximum density of matter is reached, which is 15 times greater than the nuclear one. Neutron stars are the densest objects in the universe. If you try to further increase the density of matter, it will collapse into a black hole, or a quark star will form.
Now these objects are studied by calculating complex mathematical models on supercomputers.
A magnetic field
Neutron stars have rotation speeds up to 1000 revolutions per second. In this case, electrically conductive plasma and nuclear matter generate magnetic fields of gigantic magnitudes.
For example, the magnetic field of the Earth is -1 gauss, of a neutron star - 10,000,000,000,000 gauss. The strongest field created by man will be billions of times weaker.
Types of neutron stars
Pulsars
This is a generic name for all neutron stars. Pulsars have a well-defined rotation period that does not change for a very long time. Due to this property, they are called "beacons of the universe" 
Particles fly out through the poles in a narrow stream at very high speeds, becoming a source of radio emission. Due to the mismatch of the axes of rotation, the direction of the flow is constantly changing, creating a beacon effect. And, like every lighthouse, pulsars have their own signal frequency, by which it can be identified.
Virtually all discovered neutron stars exist in double X-ray systems or as single pulsars.
magnetars
When a very rapidly spinning neutron star is born, the combined rotation and convection creates an enormous magnetic field. This happens due to the process of "active dynamo". This field exceeds the fields of ordinary pulsars by tens of thousands of times. The action of the dynamo ends in 10 - 20 seconds, and the star's atmosphere cools, but the magnetic field has time to reappear during this period. It is unstable, and a rapid change in its structure generates the release of a gigantic amount of energy. It turns out that the star's magnetic field is tearing it apart. There are about a dozen candidates for the role of magnetars in our galaxy. Its appearance is possible from a star exceeding at least 8 times the mass of our Sun. Their dimensions are about 15 km in diameter, with a mass of about one solar mass. But sufficient confirmation of the existence of magnetars has not yet been received.
X-ray pulsars.
They are considered to be another phase of the life of a magnetar and emit exclusively in the X-ray range. Radiation occurs as a result of explosions that have a certain period.
Some neutron stars appear in binary systems or acquire a companion by capturing it in their gravitational field. Such a companion will give its substance to an aggressive neighbor. If the companion of a neutron star is no less than the Sun in mass, then interesting phenomena are possible - bursters. These are X-ray flashes, lasting seconds or minutes. But they are able to increase the luminosity of a star up to 100 thousand solar. Hydrogen and helium transferred from the companion are deposited on the surface of the burster. When the layer becomes very dense and hot, a thermonuclear reaction starts. The power of such an explosion is incredible: on every square centimeter of a star, power is released, equivalent to the explosion of the entire earth's nuclear potential.
In the presence of a giant companion, matter is lost to it in the form of a stellar wind, and the neutron star draws it in with its gravity. The particles fly along the lines of force towards the magnetic poles. If the magnetic axis and the axis of rotation do not coincide, the brightness of the star will be variable. It turns out an X-ray pulsar.
millisecond pulsars.
They are also associated with binary systems and have the shortest periods (less than 30 milliseconds). Contrary to expectations, they are not the youngest, but quite old. An old and slow neutron star absorbs the matter of a giant companion. Falling on the surface of the invader, the matter gives it rotational energy, and the rotation of the star increases. Gradually, the companion will turn into, losing in mass.
Exoplanets near neutron stars
It was very easy to find a planetary system near the pulsar PSR 1257 + 12, 1000 light years away from the Sun. Near the star are three planets with masses of 0.2, 4.3 and 3.6 Earth masses with periods of revolution of 25, 67 and 98 days. Later, another planet was found with the mass of Saturn and a period of revolution of 170 years. A pulsar with a planet slightly more massive than Jupiter is also known.
In fact, it is paradoxical that there are planets near the pulsar. A neutron star is born as a result of a supernova explosion, and it loses most of its mass. The rest no longer has enough gravity to hold the satellites. Probably, the found planets were formed after the cataclysm.
Research
The number of known neutron stars is about 1200. Of these, 1000 are considered radio pulsars, and the rest are identified as X-ray sources. It is impossible to study these objects by sending any apparatus to them. In the Pioneer ships, messages were sent to sentient beings. And the location of our solar system is indicated precisely with an orientation to the pulsars closest to the Earth. From the Sun, the lines show the directions to these pulsars and the distances to them. And the discontinuity of the line indicates the period of their circulation.
Our nearest neutron neighbor is 450 light years away. This is a binary system - a neutron star and a white dwarf, the period of its pulsation is 5.75 milliseconds.
It is hardly possible to be close to a neutron star and stay alive. One can only fantasize about this topic. And how can one imagine the magnitudes of temperature, magnetic field and pressure that go beyond the boundaries of reason? But pulsars will still help us in the development of interstellar space. Any, even the most distant galactic journey, will not be disastrous if stable beacons, visible in all corners of the Universe, work.
