Constant radial flux of solar plasma. crowns in interplanetary production. The flow of energy coming from the bowels of the Sun heats the plasma of the corona up to 1.5-2 million K. Post. heating is not balanced by the loss of energy due to radiation, since the density of the corona is low. Excess energy means. degree carry away h-tsy S. century. (=1027-1029 erg/s). The crown, therefore, is not in hydrostatic. equilibrium, it is constantly expanding. According to the composition of S. century. does not differ from the plasma of the corona (S. century contains chiefly arr. protons, electrons, a few helium nuclei, oxygen ions, silicon, sulfur, and iron). At the base of the corona (10,000 km from the solar photosphere), the particles have a radial velocity of the order of hundreds of m/s, at a distance of several. solar radii, it reaches the speed of sound in plasma (100 -150 km / s), near the Earth's orbit, the speed of protons is 300-750 km / s, and their space. concentration - from several. h-ts up to several tens of fractions in 1 cm3. With the help of interplanetary space. stations it was found that up to the orbit of Saturn, the flux density of the h-c S. century. decreases according to the law (r0/r)2, where r is the distance from the Sun, r0 is the initial level. S. v. carries with it the loops of the lines of force of the suns. magn. fields, to-rye form interplanetary magn. field. Combination of radial movement of h-c S. century. with the rotation of the Sun gives these lines the shape of spirals. Large-scale structure of the magnet. The field in the vicinity of the Sun has the form of sectors, in which the field is directed away from the Sun or towards it. The size of the cavity occupied by the SV is not exactly known (its radius, apparently, is not less than 100 AU). At the boundaries of this cavity dynamic. S.'s pressure must be balanced by the pressure of interstellar gas, galactic. magn. fields and galactic space rays. In the vicinity of the Earth, the collision of the flow of c-c S. v. with geomagnetic field generates a stationary shock wave in front of the Earth's magnetosphere (from the side of the Sun, Fig.).

Impact of the solar wind with the Earth's magnetosphere: 1 - magnetic field lines. fields of the Sun; 2 - shock wave; 3 - Earth's magnetosphere; 4 - boundary of the magnetosphere; 5 - Earth's orbit; 6 - trajectory of the solar wind. S. v. as if it flows around the magnetosphere, limiting its extent in the pr-ve. Changes in the intensity of S. century associated with solar flares, yavl. main the cause of geomagnetic disturbances. fields and magnetospheres (magnetic storms). During the year, the Sun loses from S. in. \u003d 2X10-14 part of its mass Msun. It is natural to assume that an outflow of water, similar to S. V., also exists in other stars (). It should be especially intense for massive stars (with a mass = several tens of Msolns) and with a high surface temperature (= 30-50 thousand K) and for stars with an extended atmosphere (red giants), because in In the first case, parts of a highly developed stellar corona have a sufficiently high energy to overcome the attraction of the star, and in the second, they have a low parabolic. speed (escape speed; (see SPACE SPEEDS)). Means. mass losses with the stellar wind (= 10-6 Msol/yr and more) can significantly affect the evolution of stars. In turn, the stellar wind creates hot gas in the interstellar medium - X-ray sources. radiation.


A continuous stream of solar-derived plasma propagating approximately radially from the Sun and filling the Solar System to the heliocentric. distances R ~ 100 a.u. e.s.v. gas dynamic is formed. expansion of the solar corona (cf. Sun) into interplanetary space. At high temperatures, which exist in the solar corona (1.5 * 10 9 K), the pressure of the overlying layers cannot balance the gas pressure of the corona substance, and the corona expands.

The first evidence of the existence of post. plasma flux from the Sun obtained by L. Birman (L. Biermann) in the 1950s. on the analysis of the forces acting on the plasma tails of comets. In 1957, J. Parker (E. Parker), analyzing the equilibrium conditions of the substance of the crown, showed that the crown cannot be in hydrostatic conditions. in 1959. Existence post. The outflow of plasma from the Sun was proved as a result of many months of measurements on the Amer. space apparatus in 1962.

Wed S.'s characteristics are given in table. 1. Flows of S. in. can be divided into two classes: slow - with a speed of 300 km / s and fast - with a speed of 600-700 km / s. Fast streams come from regions of the solar corona, where the structure of the magnetic. field is close to radial. coronal holes. Slow flowspp. V. associated, apparently, with the areas of the crown, in which there is a means Tab. 1. - Average characteristics of the solar wind in Earth's orbit

Speed

Proton concentration

Proton temperature

Electron temperature

Magnetic field strength

Python Flux Density....

2.4*10 8 cm -2 *c -1

Kinetic energy flux density

0.3 erg*cm -2 *s -1

Tab. 2.- Relative chemical composition of the solar wind

Relative content

Relative content

In addition to the main the components of S. century - protons and electrons, - particles were also found in its composition. Measurements of ionization. temperature of ions S. century. make it possible to determine the electron temperature of the solar corona.

In S. century. differences are observed. types of waves: Langmuir, whistlers, ion-sound, Plasma waves). Some of the Alfvén type waves are generated on the Sun, and some are excited in the interplanetary medium. The generation of waves smooths out the deviations of the function of the distribution of particles from the Maxwellian and, in conjunction with the influence of the magnetic. field on the plasma leads to the fact that S. century. behaves like a continuum. Waves of the Alfvén type play a large role in the acceleration of the small components of C.

Rice. 1. The mass spectrum of the solar wind. On the horizontal axis - the ratio of the mass of the particle to its charge, on the vertical - the number of particles registered in the energy window of the device for 10 s. The numbers with the icon indicate the charge of the ion.

S.'s stream in. is supersonic in relation to the speeds of those types of waves, to-rye provide eff. energy transfer in S. century. (Alfven, sonic and magnetosonic waves). Alvenovskoye and sound Mach number C. V. 7. When flowing around S. in. obstacles capable of effectively deflecting it (the magnetic fields of Mercury, Earth, Jupiter, Saturn or the conducting ionospheres of Venus and, apparently, Mars), an outgoing bow shock wave is formed. Magnetosphere of the Earth, Magnetosphere of planets). In the case of interaction S. century. with a non-conducting body (eg, the Moon), a shock wave does not occur. The plasma flow is absorbed by the surface, and a cavity is formed behind the body, which is gradually filled with plasma C. V.

The stationary process of corona plasma outflow is superimposed by nonstationary processes associated with flares on the sun. With strong outbreaks, matter is ejected from the bottom. regions of the corona into the interplanetary medium. magnetic variations).

Rice. 2. Propagation of an interplanetary shock wave and ejecta from a solar flare. The arrows show the direction of motion of the solar wind plasma,

Rice. 3. Types of solutions to the corona expansion equation. The speed and distance are normalized to the critical speed vc and the critical distance Rc. Solution 2 corresponds to the solar wind.

The expansion of the solar corona is described by a system of ur-tions of conservation of mass, v k) on some critical. distance R to and subsequent expansion at supersonic speed. This solution gives a vanishingly small value of the pressure at infinity, which makes it possible to match it with the low pressure of the interstellar medium. Yu. Parker called the course of this type S. century. , where m is the mass of the proton, is the adiabatic index, is the mass of the Sun. On fig. 4 shows the change in expansion rate with heliocentric.

Rice. 4. Solar wind velocity profiles for the isothermal corona model at various values ​​of coronal temperature.

S. v. provides the main outflow of thermal energy of the corona, since heat transfer to the chromosphere, el.-mag. corona radiation and electronic thermal conductivitypp. V. insufficient to establish the thermal balance of the corona. Electronic thermal conductivity provides a slow decrease in the temperature of S. in. with distance. luminosity of the sun.

S. v. carries the coronal magnetic field with it into the interplanetary medium. field. The lines of force of this field frozen into the plasma form the interplanetary magnetic field. field (MMP). Although the intensity of the IMF is small and its energy density is approx. 1% of the density of the kinetic. energy S. v., it plays an important role in the thermodynamics of S. V. and in the dynamics of S.'s interactions. with the bodies of the solar system, as well as the flows of S. in. between themselves. Combination of S.'s expansion. with the rotation of the Sun leads to the fact that the magn. the lines of force frozen in the S. century have the form, B R and the azimuth components of the magnetic. fields change differently with distance near the plane of the ecliptic:

where - ang. sun rotation speed And - radial component of velocity c., index 0 corresponds to the initial level. At a distance of the Earth's orbit, the angle between the direction of the magnetic. fields and R about 45°. At large L magn.

Rice. 5. The shape of the field line of the interplanetary magnetic field. is the angular velocity of the Sun, and is the radial component of the plasma velocity, R is the heliocentric distance.

S. v., arising over the regions of the Sun with decomp. magnetic orientation. fields, speed, temp-pa, concentration of particles, etc.) also cf. regularly change in the cross section of each sector, which is associated with the existence of a fast S. flow within the sector. The boundaries of the sectors are usually located in the intraslow flow of S. at. Most often, 2 or 4 sectors are observed, rotating with the Sun. This structure which is formed at S.'s pulling out of century. large-scale magnetic field of the crown, can be observed for several. revolutions of the sun. The sectoral structure of the IMF is a consequence of the existence of a current sheet (TS) in the interplanetary medium, which rotates together with the Sun. TS creates a magnetic surge. fields - radial IMF components have different signs on different sides of the TS. This TS, predicted by H. Alfven, passes through those parts of the solar corona, which are associated with active regions on the Sun, and separates these regions from decomp. signs of the radial component of the solar magnet. fields. The TS is located approximately in the plane of the solar equator and has a folded structure. The rotation of the Sun leads to the twisting of the CS folds into a spiral (Fig. 6). Being near the plane of the ecliptic, the observer turns out to be either above or below the CS, due to which he falls into sectors with different signs of the IMF radial component.

Near the Sun in the N. century. there are longitudinal and latitudinal velocity gradients of collisionless shock waves (Fig. 7). First, a shock wave is formed that propagates forward from the boundary of the sectors (a direct shock wave), and then a reverse shock wave is formed that propagates towards the Sun.

Rice. 6. Shape of the heliospheric current sheet. Its intersection with the plane of the ecliptic (inclined to the equator of the Sun at an angle of ~ 7°) gives the observed sectoral structure of the interplanetary magnetic field.

Rice. 7. Structure of the sector of the interplanetary magnetic field. The short arrows show the direction of the solar wind plasma flow, the arrow lines show the magnetic field lines, the dash-dotted line shows the sector boundaries (the intersection of the figure plane with the current sheet).

Since the velocity of the shock wave is less than the velocity of the SW, the plasma entrains the reverse shock wave in the direction away from the Sun. Shock waves near the sector boundaries are formed at distances of ~1 AU. e. and can be traced to distances of several. A. e. These shock waves, like interplanetary shock waves from solar flares and circumplanetary shock waves, accelerate particles and are thus a source of energetic particles.

S. v. extends to distances of ~100 AU. That is, where the pressure of the interstellar medium balances the dynamic. S.'s pressure The cavity swept up by S. in. interplanetary environment). ExpandingS. V. together with the magnet frozen into it. field prevents penetration into the solar system galactic. space rays of low energies and leads to cosmic variations. beams of high energy. A phenomenon analogous to S. V., found in some other stars (see. Stellar wind).

sunny wind

is a constant radial outflow of plasma from the solar corona (See solar corona) into interplanetary space. S.'s education associated with the flow of energy entering the corona from the deeper layers of the Sun. Apparently, magnetohydrodynamic and weak shock waves transfer energy (see Plasma, Sun). To maintain S. century. it is essential that the energy carried by waves and heat conduction be transferred to the upper layers of the corona. The constant heating of the corona, which has a temperature of 1.5-2 million degrees, is not balanced by the loss of energy due to radiation, because corona density is low. Excess energy is carried away by S.'s particles.

Essentially S. century. is the continuously expanding solar corona. The pressure of the heated gas causes its stationary hydrodynamic outflow with a gradually increasing speed. At the base of the corona (solar wind 10,000 km from the surface of the Sun) particles have a radial velocity of the order of hundreds m/sec. at a distance of several radii from the Sun, it reaches a sound velocity in plasma of 100-150 km/sec, and at a distance of 1 a. e. (near the Earth's orbit) the velocity of plasma protons is 300-750 km/sec. Near the Earth's orbit, the temperature of the SV plasma, which is determined from the thermal component of particle velocities (from the difference in particle velocities and the average velocity of the flow), during quiet periods of the Sun is 10 4 K, and during active periods reaches 4․10 5 K. C . V. contains the same particles as the solar corona, i.e., mainly protons and electrons, there are also helium nuclei (from 2 to 20%). Depending on the state of solar activity, the proton flux near the Earth's orbit varies from 5․10 7 to 5․10 8 protons/( cm 2 ․sec), and their spatial concentration - from several particles to several tens of particles in 1 cm 3 . With the help of interplanetary space stations, it has been established that, up to the orbit of Jupiter, the particle flux density of the S. changes by law r –2 , Where r- distance from the Sun. The energy that is carried into interplanetary space by particles of solar energy. in 1 sec, estimated at 10 27 -10 29 erg(energy of electromagnetic radiation of the Sun Solar wind4․10 33 erg/sec). The sun loses from S. in. during the year a mass equal to the solar wind 2․10 -14 solar masses. S. v. takes with it loops of force lines of the solar magnetic field (because the lines of force are, as it were, "frozen" into the outflowing plasma of the solar corona; see Magnetohydrodynamics). The combination of the rotation of the Sun with the radial motion of particles. S. v. gives the lines of force the shape of spirals. At the level of the Earth's orbit, the strength of the magnetic field of the S. v. varies from 2.5․10–6 to 4․10–4 uh. The large-scale structure of this field in the ecliptic plane has the form of sectors in which the field is directed away from the Sun or towards it (Fig. 1). During the period of low activity of the Sun (1963-64), 4 sectors were observed, which persisted for 1.5 years. With an increase in activity, the structure of the field became more dynamic, and the number of sectors also increased.

The magnetic field carried away by S. V. partially "sweeps" galactic cosmic rays from the circumsolar space, which leads to a change in their intensity on Earth. The study of variations in cosmic rays makes it possible to investigate the solar radiation. at large distances from the Earth and, most importantly, outside the plane of the ecliptic. About many properties of S. in. Far from the Sun, it will apparently also be possible to learn from a study of the interaction of the S. plasma. with the plasma of comets - a kind of space probes. The size of the cavity occupied by the SV is not known exactly (the equipment of space stations has so far traced the SV to the orbit of Jupiter). At the boundaries of this cavity, the dynamic pressure of the S. century. must be balanced by the pressure of interstellar gas, the galactic magnetic field, and galactic cosmic rays. The collision of a supersonic solar plasma flow with the geomagnetic field generates a stationary shock wave in front of the Earth's magnetosphere (Fig. 2). S. v. as if it flows around the magnetosphere, limiting its extent in space (see Earth). The flow of particles S. in. the geomagnetic field is compressed from the solar side (here the boundary of the magnetosphere passes at a distance of 10 R ⊕ solar wind - Earth's radii) and is extended in the antisolar direction by tens of R ⊕ (the so-called "tail" of the magnetosphere). In the layer between the wave front and the magnetosphere, there is no longer a quasi-regular interplanetary magnetic field, the particles move along complex trajectories and some of them can be captured in the Earth's radiation belts. Changes in the intensity of S. century. are the main cause of disturbances in the geomagnetic field (see Magnetic Variations), magnetic storms (See magnetic storms), auroras (see Auroras), heating of the Earth's upper atmosphere, and a number of biophysical and biochemical phenomena (see Solar-terrestrial relations). The sun is not distinguished by anything special in the world of stars, so it is natural to assume that an outflow of matter, similar to S. V., also exists in other stars. Such a "stellar wind", more powerful than that of the Sun, was discovered, for example, in hot stars with a surface temperature of 30-50 thousand K. The term "S. V." was proposed by the American physicist E. Parker (1958), who developed the foundations of the hydrodynamic theory of SV.

Lit.: Parker E., Dynamic processes in the interplanetary medium, trans. from English, M., 1965; Solar wind, trans. from English, M., 1968; Hundhausen, A., Coronal expansion and solar wind, transl. from English, M., 1976.

M. A. Livshits, S. B. Pikelner.


Great Soviet Encyclopedia. - M.: Soviet Encyclopedia. 1969-1978 .

See what the "solar wind" is in other dictionaries:

    Constant radial flux of solar plasma. corona into interplanetary right. The flow of energy coming from the bowels of the Sun heats the plasma of the corona up to 1.5 2 million K. Post. heating is not balanced by the loss of energy due to radiation, since the density of the corona is low. ... ... Physical Encyclopedia

    Modern Encyclopedia

    SOLAR WIND, a steady flow of charged particles (mainly protons and electrons) accelerated by the high temperature of the solar CORONA to speeds large enough for the particles to overcome the gravity of the Sun. The solar wind deflects... Scientific and technical encyclopedic dictionary

    sunny wind- SOLAR WIND, the plasma flow of the solar corona, filling the solar system up to a distance of 100 astronomical units from the Sun, where the pressure of the interstellar medium balances the dynamic pressure of the flow. The main composition is protons, electrons, nuclei ... Illustrated Encyclopedic Dictionary

    Outflow of solar corona plasma into interplanetary space. At the level of the Earth's orbit, the average speed of solar wind particles (protons and electrons) is about 400 km/s, the number of particles is several tens per 1 cm³ ... Big Encyclopedic Dictionary

    - "SOLAR WIND", USSR, SCREEN (OSTANKINO), 1982, color. TV series. The heroine of the film novel is a young scientist Nadezhda Petrovskaya, who works on problems that are at the intersection of various sciences. Andrey Popov's last film work (39 film roles). IN… … Cinema Encyclopedia

    This term has other meanings, see Solar wind (film) ... Wikipedia

    Outflow of solar corona plasma into interplanetary space. At the level of the Earth's orbit, the average speed of solar wind particles (protons and electrons) is about 400 km/s, the number of particles varies from a few to several tens per 1 cm3. * * *… … encyclopedic Dictionary

sunny wind

The sun is the source of a constant stream of particles. Neutrinos, electrons, protons, alpha particles, and heavier atomic nuclei all together make up the corpuscular radiation of the Sun. A significant part of this radiation is a more or less continuous outflow of plasma, the so-called solar wind, which is a continuation of the outer layers of the solar a

atmosphere - the solar corona. Near the Earth, its speed is usually 400–500 km/s. A stream of charged particles is ejected from the Sun through coronal holes - regions in the Sun's atmosphere with a magnetic field open into interplanetary space. The sun rotates with a period of 27 days. The trajectories of solar wind particles moving along the lines of magnetic field induction have a spiral structure due to the rotation of the Sun. As a result of the rotation of the Sun, the geometric shape of the solar wind flow will be an Archimedean spiral. On days of solar storms, the solar wind increases sharply. It causes auroras and magnetic storms on Earth, and astronauts should not go into outer space at this time. Under the influence of the solar wind, the tails of comets are always directed away from the Sun. The sun is a powerful source of radio emission. Centimeter radio waves emitted by the chromosphere and longer waves emitted by the corona penetrate into interplanetary space.

Planet Mercury

Mercury is the closest planet to the Sun and takes just 88 days to complete its entire orbit around the Sun. Mercury is the smallest of all the planets, apart from Pluto. The surface of this little world is hot enough to melt tin and lead. There is hardly any atmosphere there, and the solid ground is all covered with craters.

  • Weight: 3.3*1023 kg. (0.055 Earth masses);
  • Equator diameter: 4870 km. (0.38 the diameter of the Earth's equator);
  • Density: 5.43 g/cm3
  • Surface temperature: maximum 480°C, minimum -180°C
  • 58.65 Earth days
  • 0.387 AU, that is, 58 million km
  • 88 earth days
  • Period of revolution around its own axis (day): 176 earth days
  • Orbital inclination to the ecliptic: 7°
  • Orbital eccentricity: 0,206
  • 47.9 km/s
  • 3.72 m/s2
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The structure of the planet Mercury

Based on the analysis of photographs of Mercury, American geologists P. Schultz and D. Gault proposed the following scheme for the evolution of its surface. After the completion of the accumulation process and the formation of the planet, its surface was smooth. Then came the process of intense bombardment of the planet by the remnants of the planetary swarm, during which pools of the Caloris type were formed, as well as craters of the Copernicus type on the Moon. The next period was characterized by intense volcanism and the release of a lava flow that filled large basins. This period ended about 3 billion years ago. Mercury has a weak magnetic field, it is 0.7% of the earth's magnetic field. The magnetic field of the planet has a more complex structure than the earth's. In addition to the dipole (two-pole) field, it also contains fields with four and eight poles. From the side of the Sun, Mercury's magnetosphere is strongly compressed by the solar wind. The high density and the presence of a magnetic field indicate that Mercury must have a dense metallic core. The density in the center of Mercury should reach 9.8 g/cm3, the radius of the core is 1800 km (75% of the radius of the planet). The core accounts for 80% of Mercury's mass. Despite the slow rotation of the planet, its magnetic field is excited by the same dynamo mechanism as the Earth's magnetic field. This mechanism is reduced to the formation of ring electric currents in the core of the planet during its rotation, which generate a magnetic field. Above the massive core is a silicate shell 600 km thick. The density of surface rocks is about 3.3 g/cm3. Data on the atmosphere of Mercury indicates only its strong rarefaction. The pressure at the surface of the planet is 500 billion times less than at the surface of the Earth. Mercury is located very close to the Sun and captures the solar wind with its gravity. A helium atom captured by Mercury stays in the atmosphere for an average of 200 days. In addition to helium, the presence of hydrogen was registered on Mercury. In addition, hot, like a furnace, solid rocks emit various atoms, including alkali metal atoms, which are recorded in the spectrum of the atmosphere. The presence of carbon dioxide and carbon monoxide is suspected.

Surface of the planet Mercury

The surface of Mercury was dotted with a grid of craters of various sizes. Their size distribution was similar to that of the moon. Most of the craters were formed as a result of the fall of meteorites. On the surface of the planet, smooth rounded plains were discovered, which received the name of basins by their resemblance to the lunar "seas". The appearance of valleys is explained by intense volcanic activity, which coincided in time with the formation of the planet's surface. There are mountains on Mercury, the height of the highest reaches 2–4 km. In a number of regions of the planet, valleys and craterless plains are visible on the surface. On Mercury, there is also an unusual detail of the relief - the scarp. This is a 2–3 km high protrusion separating two surface areas. The scarps formed as shifts during the early contraction of the planet. Mercury's polar regions may have water ice. The inner regions of the craters located there are never illuminated by the Sun, and the temperature there can be around -210 ° C. Mercury's albedo is extremely low, around 0.11. The maximum surface temperature of Mercury is +410°С. Temperature differences due to the change of seasons caused by the elongation of the orbit reach 100°C on the day side. the average temperature of the nighttime ranan hemisphere is –162°C (111 K). On the other hand, the temperature of the subsolar point at the average distance of Mercury from the Sun is +347°С. The surface of this small world is hot enough to melt lead or tin.

Planet Venus

The second largest planet from the Sun in the solar system. One of the terrestrial planets, similar in nature to the Earth, but smaller in size. Like the Earth, it is surrounded by a fairly dense atmosphere. Venus comes closer to the Earth than any other planet and is the brightest celestial object (except for the Sun and Moon). The light of Venus is so bright that if there is neither the Sun nor the Moon in the sky, it causes objects to cast shadows. Located closer to the Sun than our planet, Venus receives from it more than twice as much light and heat as the Earth. However, on the shadow side, Venus is dominated by a frost of more than 20 degrees below zero, since the sun's rays do not fall here for a very long time. The surface of Venus is constantly covered by dense layers of clouds, due to which surface features are almost invisible in visible light,

  • Weight: 4.87*1024 kg. (0.815 Earth masses);
  • Equator diameter: 12102 km. (0.949 the diameter of the Earth's equator);
  • Density: 5.25 g/cm3
  • Surface temperature: maximum 480°C
  • Period of rotation relative to the stars: 243 Earth days
  • Distance from the Sun (average): 0.723 a.e., i.e. 108 million km
  • Orbital period (year): 224.7 Earth days
  • The period of revolution around its own axis (not equal to days, a day on Venus is 116.8 Earth days): 243.02 Earth days
  • Orbital inclination to the ecliptic: 3.39°
  • Orbital eccentricity: 0,0068
  • Average orbital speed: 35 km/s
  • Acceleration of gravity: 8.87 m/s2

The sun is the source of a constant stream of particles. Neutrinos, electrons, protons, alpha particles, and heavier atomic nuclei all together make up the corpuscular radiation of the Sun. A significant part of this radiation is a more or less continuous outflow of plasma, the so-called solar wind, which is a continuation of the outer layers of the solar atmosphere - the solar corona. Near the Earth, its speed is usually 400–500 km/s. A stream of charged particles is ejected from the Sun through coronal holes - regions in the Sun's atmosphere with a magnetic field open into interplanetary space.

The first measurements of the solar wind were made in 1959 on the Luna-9 AMS. In 1962, Mariner 2, heading for Venus, made observations of the solar wind and obtained the following results: the solar wind speed varied from 350 m/s to 800 m/s, the average concentration of the solar wind was 5.4 ions per 1 cm3 , ion temperature 160,000 K. Average magnetic field strength 6*10–5 oersted.

A lot of new information about the solar wind was found out by the international space station SOHO. It turned out that he carries elements such as nickel, iron, silicon, sulfur, calcium, chromium.

The sun rotates with a period of 27 days. The trajectories of solar wind particles moving along the lines of magnetic field induction have a spiral structure due to the rotation of the Sun. As a result of the rotation of the Sun, the geometric shape of the solar wind flow will be an Archimedean spiral, reminiscent of the shape of a jet of water from a garden hose rotating around an axis.

On days of solar storms, the solar wind increases sharply. It causes auroras and magnetic storms on Earth, and astronauts should not go into outer space at this time.

Under the influence of the solar wind, the tails of comets are always directed away from the Sun. The Voyager spacecraft detected the solar wind even beyond the orbit of Pluto. In fact, we live in a giant heliosphere formed by the solar wind, although protected from it by the Earth's magnetic field.

The sun is a powerful source of radio emission. Centimeter radio waves emitted by the chromosphere and longer waves emitted by the corona penetrate into interplanetary space.

If in the visible rays the Sun radiates relatively stably (changes occur by fractions of a percent), then in the radio range the radiation can change hundreds and even thousands of times. The radio emission of the Sun has two components - constant and variable. The constant component characterizes the radio emission of the quiet Sun. The solar corona radiates radio waves as an absolutely black body with a temperature of T = 106 K. The variable component of the Sun's radio emission manifests itself in the form of bursts, noise storms. Noise storms last from several hours to several days. 10 minutes after a strong solar flare, the radio emission of the Sun increases thousands and even millions of times compared to the radio emission of the quiet Sun and lasts from several minutes to several hours. This radio emission has a non-thermal nature.

Sunny wind.

In the late 1950s, the American astrophysicist Eugene Parker came to the conclusion that, since the gas in the solar corona has a high temperature that persists with distance from the Sun, it must continuously expand, filling the solar system. The results obtained with the help of Soviet and American spacecraft confirmed the correctness of Parker's theory.
In interplanetary space, a flow of matter directed from the Sun, called the solar wind, really rushes. It represents a continuation of the expanding solar corona; It consists mainly of the nuclei of hydrogen atoms (protons) and helium (alpha particles), as well as electrons. Particles of the solar wind fly at speeds of several hundred kilometers per second, moving away from the Sun by many tens of astronomical units - to where the interplanetary medium of the solar system passes into rarefied interstellar gas. And along with the wind, solar magnetic fields are also transferred into interplanetary space.

coronal hole.
The sun is the source of a constant stream of particles. Neutrinos, electrons, protons, alpha particles, and heavier atomic nuclei all together make up the corpuscular radiation of the Sun. A significant part of this radiation is a more or less continuous outflow of plasma, the so-called solar wind, which is a continuation of the outer layers of the solar atmosphere - the solar corona. Near the Earth, its speed is usually 400–500 km/s. A stream of charged particles is ejected from the Sun through coronal holes - regions in the Sun's atmosphere with a magnetic field open into interplanetary space.

The total magnetic field of the Sun in the form of magnetic induction lines is a bit like the earth's. But the lines of force of the earth's field near the equator are closed and do not let charged particles directed towards the Earth pass. The lines of force of the solar field, on the contrary, are open in the equatorial region and stretch into interplanetary space, bending like spirals. This will be explained by the fact that the lines of force remain connected with the Sun, which rotates around its axis. The solar wind, together with the magnetic field "frozen" in it, forms the gaseous tails of comets, directing them away from the Sun. Meeting the Earth on its way, the solar wind strongly deforms its magnetosphere, as a result of which our planet has a long magnetic "tail", also directed away from the Sun. The Earth's magnetic field sensitively responds to the streams of solar matter blowing over it.