On September 1, 1859, two English astronomers, Richard Carrington and S. Hodgson, independently observing the Sun in white light, saw something like lightning flash suddenly among one group sunspots. This was the first observation of a new, as yet unknown phenomenon on the Sun; it was later named solar flare.
What is a solar flare? In short, this is the strongest explosion on the Sun, as a result of which an enormous amount of energy accumulated in a limited volume of the solar atmosphere is quickly released.
Flashes most often occur in neutral regions. located between large spots of opposite polarity. Typically, the development of a flash begins with a sudden increase in brightness flare site- regions of a brighter, and hence hotter, photosphere. Then a catastrophic explosion occurs, during which the solar plasma heats up to 40-100 million K. This manifests itself in a multiple increase in the short-wave radiation of the Sun (ultraviolet and X-ray), as well as in an increase in the "radio voice" of the daylight and in the release of accelerated solar corpuscles (particles) . And in some of the most powerful flares, even solar cosmic rays are generated, the protons of which reach speeds equal to half the speed of light. Such particles have deadly energy. They are able to penetrate almost unhindered spaceship and destroy the cells of a living organism. Therefore, solar cosmic rays can pose a serious danger to the crew caught in flight by a sudden flash.
Thus, solar flares emit radiation in the form electromagnetic waves and in the form of particles of matter. Gain electromagnetic radiation happening in wide range wavelengths - from hard X-rays and gamma rays to kilometer radio waves. At the same time, the total flow visible radiation remains constant to the nearest fraction of a percent. . Weak flares on the Sun almost always occur, and large ones - once every few months. But during the years of maximum solar activity, large solar flares occur several times a month. Usually a small flash lasts 5 - 10 minutes; the most powerful - a few hours. During this time, a plasma cloud with a mass of up to 10 billion tons is ejected into the near-solar space and energy is released equivalent to the explosion of tens or even hundreds of millions. hydrogen bombs! However, the power of even the largest flares does not exceed hundredths of a percent of the power of the total solar radiation. Therefore, during a flash, there is no noticeable increase in the luminosity of our daylight.
During the flight of the first crew on the American orbital station Skylab (May-June 1973) was able to photograph the flare in the light of iron vapor at a temperature of 17 million K, which should be hotter than at the center of the solar fusion reactor. And in last years Gamma-ray pulses were registered from several flares.
Such impulses probably owe their origin to annihilation of electron-positron pairs. The positron is known to be the antiparticle of the electron. It has the same mass as an electron, but is endowed with the opposite electric charge. When an electron and a positron collide, which can happen in solar flares, they are immediately annihilated, turning into two gamma-ray photons.
Like any heated body, the Sun continuously emits radio waves. The thermal radio emission of the quiet Sun, when there are no spots and flares on it, constantly comes from the chromosphere both at millimeter and centimeter waves, and from the corona at meter waves. But as soon as large spots appear, a flash occurs, strong radio bursts appear against the background of calm radio emission ... And then the radio emission of the Sun increases abruptly by thousands, or even millions of times!
The physical processes leading to the occurrence of solar flares are very complex and still poorly understood. However, the very fact that solar flares appear almost exclusively in large groups spots indicates family ties flares with strong magnetic fields on the Sun. And the flash is, apparently, nothing more than a grandiose explosion caused by the sudden compression of the solar plasma under the pressure of a strong magnetic field. It is the energy of the magnetic fields, somehow released, that generates a solar flare.
Radiation from solar flares often reaches our planet, providing strong impact to the upper layers of the earth's atmosphere (ionosphere). They also lead to the occurrence of magnetic storms and auroras.
Consequences of solar flares
On February 23, 1956, the stations of the Service of the Sun noted a powerful flash in the daylight. An explosion of unprecedented force threw giant clouds of incandescent plasma into the near-solar space - each many times over. more earth! And with a speed of more than 1000 km / s, they rushed towards our planet. The first echoes of this catastrophe quickly reached us through the cosmic abyss. Approximately 8.5 minutes after the outbreak began, a greatly increased flux of ultraviolet and X-rays reached the upper layers of the earth's atmosphere - the ionosphere, increased its heating and ionization. This led to sharp deterioration and even a temporary cessation of short-wave radio communications, because instead of being reflected from the ionosphere, as from a screen, they began to be intensively absorbed by it ...
Sometimes, with very strong flashes, radio interference lasts for several days in a row, until the restless luminary "comes back to normal." The dependence is traced here so clearly that the frequency of such interference can be used to judge the level of solar activity. But the main perturbations caused on Earth by the flare activity of the star are ahead.
Following the short-wave radiation (ultraviolet and X-rays) of our planet, a stream of high-energy solar cosmic rays. True, the magnetic shell of the Earth protects us quite reliably from these deadly rays. But for astronauts working in open space, they pose a very serious danger: exposure can easily exceed the allowable dose. That is why about 40 observatories of the world constantly participate in the patrol service of the Sun - they conduct continuous observations of the flare activity of the daytime star.
Further development of geophysical phenomena on Earth can be expected in a day or two days after the outbreak. It is this time - 30-50 hours - required for the plasma clouds to reach the earth's "environs". After all, a solar flare is something like a space gun that shoots into interplanetary space with corpuscles - particles of solar matter: electrons, protons (nuclei of hydrogen atoms), alpha particles (nuclei of helium atoms). The mass of corpuscles erupted by the outbreak in February 1956 amounted to billions of tons!
As soon as the clouds of solar particles collided with the Earth, the compass needles darted, and the night sky above the planet was decorated with multi-colored flashes of the aurora. Among patients, heart attacks have become more frequent, and the number of road accidents has increased.
What is there magnetic storms, auroras... Literally the entire globe shuddered under the pressure of gigantic corpuscular clouds: in many seismic zones earthquakes have occurred. And, as it were, to top it all off, the duration of the day changed abruptly by as much as 10 ... microseconds!
Space research has shown that the globe is surrounded by a magnetosphere, that is, a magnetic shell; inside the magnetosphere, the strength of the terrestrial magnetic field prevails over the strength of the interplanetary field. And in order for the flare to have an impact on the Earth's magnetosphere and the Earth itself, it must occur at a time when the active region on the Sun is located near the center solar disk, that is, it is oriented towards our planet. Otherwise, all flare radiations (electromagnetic and corpuscular) will rush sideways.
Plasma that rushes from the surface of the Sun into space, has a certain density and is able to exert pressure on any obstacles encountered in its path. Such a significant obstacle is the Earth's magnetic field - its magnetosphere. It counteracts the flow of solar matter. There comes a moment when both pressures are balanced in this confrontation. Then the boundary of the Earth's magnetosphere, compressed by the solar plasma flow from the day side, is set at a distance of about 10 Earth radii from the surface of our planet, and the plasma, not being able to move straight, begins to flow around the magnetosphere. At the same time, particles of solar matter pull out its magnetic lines of force, and on the night side of the Earth (in the opposite direction from the Sun), a long plume (tail) is formed near the magnetosphere, which extends beyond the orbit of the Moon. The earth with its magnetic shell is inside this corpuscular flow. And if ordinary sunny wind, constantly flowing around the magnetosphere, can be compared with a light breeze, then the rapid flow of corpuscles generated by a powerful solar flare is like a terrible hurricane. When such a hurricane strikes a magnetic shell the globe, it is compressed even more strongly from the sunflower side and is played out on Earth magnetic storm.
In this way, solar Activity affects terrestrial magnetism. With its strengthening, the frequency and intensity of magnetic storms increases. But this connection is quite complex and consists of a whole chain physical interactions. The main link in this process is the enhanced flow of corpuscles that occurs during solar flares.
Part of the energetic corpuscles in the polar latitudes breaks out of the magnetic trap into earth's atmosphere. And then, at altitudes from 100 to 1000 km, fast protons and electrons, colliding with air particles, excite them and make them glow. As a result, there is Polar Lights.
Periodic "revival" of the great luminary is a natural phenomenon. So, for example, after a grandiose solar flare observed on March 6, 1989, corpuscular streams excited literally the entire magnetosphere of our planet. As a result, a powerful magnetic storm broke out on Earth. It was accompanied by an astounding aurora in its scope, which in the region of the California Peninsula reached tropical zone! Three days later, a new powerful outbreak occurred, and on the night of March 13-14, residents south coast The Crimeans also admired the enchanting flashes that stretched out in the starry sky above the rocky teeth of Ai-Petri. It was a unique sight, similar to the glow of a fire that immediately engulfed half the sky.
In the first half of Wednesday, September 6, 2017, scientists registered the most powerful solar flare in the last 12 years. The flare was assigned a score of X9.3 - the letter means belonging to the class of extremely large flares, and the number indicates the strength of the flare. The ejection of billions of tons of matter occurred almost in the region of AR 2673, almost in the center of the solar disk, so earthlings did not escape the consequences of what happened. The second powerful outbreak (point X1.3) was recorded on the evening of Thursday, September 7, the third - today, Friday, September 8.
The sun releases huge energy into space
Solar flares are divided into five classes depending on the X-ray power: A, B, C, M and X. The minimum class A0.0 corresponds to the radiation power in the Earth's orbit of ten nanowatts per square meter, the next letter means a tenfold increase in power. During the most powerful flares that the Sun is capable of, great energy, in a few minutes - about a hundred billion megatons of TNT. This is about a fifth of the energy radiated by the Sun in one second, and all the energy that humanity will produce in a million years (assuming it is produced at modern rates).
Severe geomagnetic storm expected
X-ray radiation reaches the planet in eight minutes, heavy particles - in a few hours, plasma clouds - in two to three days. The coronal ejection from the first flare has already reached the Earth, the planet collided with a cloud of solar plasma with a diameter of about one hundred million kilometers, although it was previously predicted that this would happen by Friday evening, September 8th. A geomagnetic storm of G3-G4 level (a five-point scale varies from weak G1 to extremely strong G5), provoked by the first outbreak, should end on Friday evening. Coronal ejections from the second and third solar flares have not yet reached the Earth, possible consequences should be expected at the end of the current - beginning of next week.
The consequences of the outbreak have long been understood
Geophysicists predict the aurora in Moscow, St. Petersburg and Yekaterinburg, cities located at relatively low latitudes for the Aurora. In the US state of Arkansas, it has already been noticed. As early as Thursday, carriers in the US and Europe reported non-critical outages. X-ray level at earth orbit increased slightly, the military clarifies that there is no direct threat to satellites and ground systems, as well as to the crew of the ISS.
Image: NASA/GSFC
However, there is a danger to low-orbit and geostationary satellites. The former are at risk of failing due to deceleration from the heated atmosphere, while the latter, having moved 36,000 kilometers from the Earth, may collide with a cloud of solar plasma. Interruptions with radio communication are possible, but for final evaluation the consequences of the outbreak must wait at least the end of the week. The deterioration of people's well-being due to changes in the geomagnetic situation has not been scientifically proven.
May increase solar activity
The last time such an outbreak was observed on September 7, 2005, but the strongest (with a score of X28) occurred even earlier (November 4, 2003). In particular, on October 28, 2003, one of the high-voltage transformers in the Swedish city of Malmö failed, de-energizing the entire locality. Other countries also suffered from the storm. A few days before the events of September 2005, a less powerful flare was recorded, and scientists believed that the Sun would calm down. What is happening in last days strongly reminiscent of that situation. This behavior of the luminary means that the 2005 record may still be broken in the near future.
Image: NASA/GSFC
However, over the past three centuries, humanity has experienced even more powerful solar flares than those that occurred in 2003 and 2005. In early September 1859, a geomagnetic storm brought down the telegraph systems of Europe and North America. The reason was called a powerful coronal mass ejection, which reached the planet in 18 hours and was observed on September 1 by British astronomer Richard Carrington. There are also studies that question the effects of the solar flare of 1859, scientists that the magnetic storm affected only local areas of the planet.
Solar flares are difficult to quantify
A consistent theory describing the formation of solar flares does not yet exist. Flares occur, as a rule, in the places of interaction of sunspots on the border of the regions of the northern and southern magnetic polarities. This leads to a rapid release of the energy of the magnetic and electric fields, which is then used to heat the plasma (increase in the velocity of its ions).
Observed spots are areas of the Sun's surface with a temperature of about two thousand degrees Celsius below the temperature of the surrounding photosphere (about 5.5 thousand degrees Celsius). In the darkest parts of the spot, the magnetic field lines are perpendicular to the surface of the Sun, in the lighter parts they are closer to the tangent. The magnetic field strength of such objects exceeds its earthly meaning thousands of times, and the outbreaks themselves are associated with abrupt change local geometry of the magnetic field.
solar flare occurred against the backdrop of a minimum solar activity. Probably, in this way the luminary releases energy and will soon calm down. Events of this kind have occurred earlier in the history of the star and the planet. The fact that this is attracting public attention today does not speak of a sudden threat to humanity, but of scientific progress- in spite of everything, scientists gradually better understand the processes occurring with the star, and report this to the taxpayers.
Where to monitor the situation
Information about solar activity can be gleaned from many sources. In Russia, for example, from the websites of two institutes: and (the first at the time of this writing posted a direct warning about the danger to satellites due to a solar flare, the second contains a convenient graph of flare activity), which use data from American and European services. Interactive data on solar activity, as well as an assessment of the current and future geomagnetic situation, can be found on the website
19:52 07/09/20170 👁 595
Scientists recorded the most powerful outbreak in 12 years on the evening of Wednesday, September 6. The outburst effect was exacerbated by the fact that it occurred close to the Sun- line, from where the influence of the Sun on ours is maximum. As a result, the level of X-ray radiation was immediately increased on the Earth. Scholars agree that most of consequences may be delayed and manifest within the next few days.
How solar flares occur and how long they last, how they can threaten people and how to understand that you are subject to their influence, the iz.ru portal understood.
What it is?
At its core, flares on the Sun are explosions, as a result of which a large amount of thermal, kinetic and light energy is ejected into the planets. Their duration is usually no more than a few minutes, however, in terms of their power, such flashes are tens of times higher than the energy of an erupting volcano.
The harbinger is the appearance of large sunspots on the Sun, which scientists can observe. Their collision leads to the outbreak - on September 6, for example, two of the largest groups of sunspots in several years collided.
Emission into the atmosphere of the Sun a large number charged particles creates the effect of a shock wave that rolls over interplanetary space at the speed of sound. Its power may vary depending on the power of the flash.
What is the peculiarity of the outbreak recorded on September 6?
Previously, scientists focused on optical signs, trying to somehow characterize the outbreak. Now the world has adopted a unified scale.
Flares produce X-rays that the Sun normally does not produce. Therefore, if such flows begin to arrive, we can confidently say that an outbreak is occurring. The stronger the radiation fluxes, the stronger the flashes occur, - says Sergey Bogachev, chief Researcher Laboratories x-ray astronomy Sun FIAN.
In this case, the level of X-ray radiation indicates the letter of the Latin alphabet preceding the number. The minimum level is indicated by the letter A, with each subsequent letter, the radiation power increases by 10 times. The outbreak that occurred the day before was rated at X9.3 points.
The highest is the letter X. That is, it cannot be higher, this is actually the limit of this scale, - says Sergey Bogachev.
What influences solar activity?
Astronauts in orbit are at risk, who, among other things, may face a radiation dose. In addition, powerful flashes can lead to interruptions in the operation of automation and navigation equipment (as happened the day before) or damage communications satellites.
Spacecraft are not protected by the Earth's atmosphere or gravitational field, so in the coming days they will probably work in conditions increased risk, there is a possibility of failure, - explains Sergey Bogachev.
On Earth, the effect of this flash will also be felt, but only its echoes will most likely reach us. The atmosphere and magnetic field protect the planet from solar influence. These two "shields", according to Sergei Bogachev, should work correctly this time as well. However, upon reaching the Earth's atmosphere, shock wave” will provoke fluctuations that will lead to the occurrence of magnetic storms - they will be felt by weather-sensitive people. Be prepared for the fact that the consequences may be felt until the end of this week.
Flash has already been studied. It can be seen that the next three days will be days of increased geomagnetic tension, the expert noted.
Another, less well-known consequence of a solar flare is the occurrence of northern lights: the Earth's magnetic field begins to glow, having taken the impact of the solar "wave".
How to understand that you are weather dependent?
The sensitivity of people to weather phenomena is not a myth. First of all, people with cardiovascular diseases suffer from them. However, everyone can react to magnetic storms in different ways. Also, if someone "feels" the outbreak right away, for some, the effect can be delayed for up to a few days.
In order to understand whether you are affected by solar activity and how much, it will take some time to observe your condition. If you periodically suffer from insomnia, headaches, pressure drops, and malaise most often happens unexpectedly and without any visible reasons, most likely, you are weather dependent.
Can you prepare for an outbreak?
It is worth paying attention to your weather dependence in order to try to take additional measures before increasing solar activity. Today, scientists can predict most of the flares - the appearance of new spots on the Sun indicates that there is an accumulation of energy, which may soon be thrown out as a result of the next "solar explosion".
Impacts on the Earth are planetary in nature. So you can't hide, but you can take precautions. Someone has a tendency to weather sensitivity, but someone does not. Those who have it usually know this about themselves. Therefore, perhaps they should just take in advance or keep at the ready the drugs that they usually take for headaches or, for example, for pressure drops, the scientist summed up.
It should be noted that solar flares and coronal mass ejections are different and independent phenomena of solar activity. The energy release of a powerful solar flare can reach 6 × 10 25 joules, which is about 1 ⁄ 6 energy released by the Sun per second, or 160 billion megatons of TNT, which, for comparison, is the approximate volume of world electricity consumption over 1 million years.
Photons from the flare reach Earth about 8.5 minutes after it began; then, within a few tens of minutes, powerful streams of charged particles reach, and plasma clouds from a solar flare reach our planet only after two or three days.
Description [ | ]
Photograph of an outbreak in 1895.
The duration of the impulsive phase of solar flares usually does not exceed a few minutes, and the amount of energy released during this time can reach billions of megatons of TNT. The flash energy is traditionally determined in the visible range of electromagnetic waves by the product of the glow area in the hydrogen emission line H α , which characterizes the heating of the lower chromosphere, and the brightness of this glow, associated with the power of the source.
In recent years, a classification based on patrol homogeneous measurements on a series of satellites, mainly GOES, of the amplitude of a thermal X-ray burst in the energy range of 0.5-10 keV (with a wavelength 0.5-8 angstroms). The classification was proposed in 1970 by D. Baker and was originally based on the measurements of the Solrad satellites. According to this classification, a solar flare is assigned a score - a designation from latin letter and an index behind it. The letter can be A, B, C, M, or X, depending on the magnitude of the X-ray intensity peak reached by the flare:
The index specifies the value of the flash intensity and can be from 1.0 to 9.9 for the letters A, B, C, M and more - for the letter X. For example, an outbreak on February 12, 2010 of M8.3 corresponds to a peak intensity of 8, 3×10 −5 W/m 2 . The most powerful (as of 2010) flare recorded since 1976, which occurred on November 4, 2003, was assigned the X28 score, thus, its X-ray intensity at the peak was 28 × 10 −4 W / m 2. It should be noted that the registration of the X-ray radiation of the Sun, since it is completely absorbed by the Earth's atmosphere, has become possible since the first launch spacecraft"Sputnik-2" with the appropriate equipment, therefore, data on the intensity of X-ray radiation of solar flares until 1957 are completely absent.
Measurements in different wavelength ranges reflect different processes in flares. Therefore, the correlation between the two indices of flare activity exists only in a statistical sense, so for individual events one index can be high and the other low, and vice versa.
Solar flares tend to occur at points of interaction between sunspots of opposite magnetic polarity, or more precisely, near the magnetic neutral line separating north and south polarity regions. The frequency and power of solar flares depend on the phase of the 11-year solar cycle.
Effects [ | ]
Solar flares have applied value, for example, in the study elemental composition surfaces celestial body with a rarefied atmosphere or in its absence, acting as an X-ray exciter for X-ray fluorescence spectrometers installed on board spacecraft.
hard ultraviolet and x-rays flares is the main factor responsible for the formation of the ionosphere, which can also significantly change the properties upper atmosphere: its density increases significantly, which leads to a rapid decrease in height satellite orbits(up to a kilometer per day). [ ]
Plasma clouds ejected during flares lead to the occurrence of geomagnetic storms, which in a certain way affect technology and biological objects.
Forecasting[ | ]
The modern forecast of solar flares is given on the basis of the analysis of the magnetic fields of the Sun. However, the magnetic structure of the Sun is so unstable that it is currently impossible to predict a flare even a week in advance. NASA predicts a very short term, from 1 to 3 days: on quiet days on the Sun, the probability of a strong flare is usually indicated in the range of 1-5%, and on active periods it increases only up to 30-40%.
The Sun has experienced the largest series of flares since February 2010. space laboratory Solar X-ray Astronomy, FIAN, informed about the details of the phenomenon that happened on heavenly body our solar system.
A series of large flares occurred on the Sun over the weekend. For two days, from June 12 to June 13, 2010, 10 events of classes C and M were recorded on the Sun. active area number 1081 in the north of the Sun. On the same day, 8 hours later, a second major event- flash class C6.1. And on June 13, it became more active and Southern Hemisphere Sun: in the area located here with the number 1079, at about 9:30 Moscow time, the third major event in two days occurred - an X-ray flare of the M1.0 level.
The last time a burst of solar activity of comparable strength was observed in winter, in February 2010. Then for 12 days from February 5 to February 16, more than fifty flares occurred on the Sun. Flare activity peaked on February 8, which was the most active day on the Sun in more than five years of observations. On this day, 22 solar flares occurred on the Sun in a day. And 4 days later, on February 12, already in the recession phase, the most powerful outbreak of the coming solar cycle- an M8.3 class event, which still remains a record.
It is not yet clear whether the events of June 12–13 are a random single burst of activity, or whether the Sun is entering another phase of growth. The last three months, from March to May, solar activity is almost continuous fell and has been at extremely low levels in recent days, close to the level of last year, which is considered one of the record solar minimums in more than 200 years of observational history. The fact that the surge that occurred may be a harbinger of an even stronger increase in activity in the coming days is indicated by the nature of the events that took place: the flares began after a long break almost synchronously in both hemispheres of the Sun. In addition, 2 new powerful sunny area with numbers 1082 and 1083. Already on June 15-16, the Earth will be in their area of influence. Finally, in recent days, the level of X-ray and radio emission from the Sun has increased significantly, indicating a rapid increase in the temperature and density of the solar corona.
In what direction the new emerging trend of solar activity will develop will become clear in the coming days.
