The movement of the earth around the center of the galaxy. Where are we going? Velocity of the Galaxy relative to the cosmic microwave background radiation

Even sitting in a chair in front of a computer screen and clicking on links, we are physically involved in a variety of movements. Where are we going? Where is the "top" of the movement? apex?

Firstly, we participate in the rotation of the Earth around its axis. This diurnal movement directed towards the east point on the horizon. The speed of movement depends on the latitude; it is equal to 465*cos(φ) m/sec. Thus, if you are at the north or south pole of the Earth, then you are not participating in this movement. Let's say in Moscow the daily linear speed is approximately 260 m/sec. Apex angular velocity diurnal movement It’s easy to calculate relative to the stars: 360° / 24 hours = 15° / hour.

Secondly, the Earth, and we along with it, moves around the Sun. (We will ignore the small monthly wobble around the center of mass of the Earth-Moon system.) Average speed annual movement in orbit - 30 km/sec. At perihelion in early January it is slightly higher, at aphelion in early July it is slightly lower, but since the Earth’s orbit is almost an exact circle, the speed difference is only 1 km/sec. The apex of the orbital motion naturally shifts and makes a full circle in a year. Its ecliptic latitude is 0 degrees, and its longitude is equal to the longitude of the Sun plus approximately 90 degrees - λ=λ ☉ +90°, β=0. In other words, the apex lies on the ecliptic, 90 degrees ahead of the Sun. Accordingly, the angular velocity of the apex is equal to the angular velocity of the Sun: 360°/year, slightly less than a degree per day.

We carry out larger-scale movements already together with our Sun as part of solar system.

First, the Sun moves relative nearest stars(so-called local rest standard). The speed of movement is approximately 20 km/sec (slightly more than 4 AU/year). Please note: this is even less than the speed of the Earth in orbit. The movement is directed towards the constellation Hercules, and the equatorial coordinates of the apex are α = 270°, δ = 30°. However, if we measure the speed relative to all bright stars , visible to the naked eye, then we get the standard movement of the Sun, it is somewhat different, lower in speed 15 km / sec ~ 3 AU. / year). This is also the constellation Hercules, although the apex is slightly shifted (α = 265°, δ = 21°). But relative to the interstellar gas, the Solar system moves slightly faster (22-25 km / sec), but the apex is significantly shifted and falls into the constellation Ophiuchus (α = 258°, δ = -17°). This apex shift of approximately 50° is associated with the so-called. "interstellar wind" "blowing from the south" of the Galaxy.

All three movements described are, so to speak, local movements, “walks in the yard.” But the Sun, together with the nearest and generally visible stars (after all, we practically do not see very distant stars), together with clouds of interstellar gas, revolves around the center of the Galaxy - and these are completely different speeds!

The speed of movement of the solar system around galactic center is 200 km/sec (more than 40 AU/year). However, the indicated value is inaccurate; it is difficult to determine the galactic speed of the Sun; We don’t even see what we are measuring the movement against: the center of the Galaxy is hidden by dense interstellar clouds of dust. The value is constantly being refined and tends to decrease; not so long ago it was taken as 230 km/sec (you can often find this value), and recent studies give results even less than 200 km/sec. The galactic movement occurs perpendicular to the direction to the center of the Galaxy and therefore the apex has galactic coordinates l = 90°, b = 0° or in more familiar equatorial coordinates - α = 318°, δ = 48°; this point is located in Lebed. Because this is a movement of reversal, the apex moves and completes a full circle in a "galactic year", approximately 250 million years; its angular velocity is ~5"/1000 years, one and a half degrees per million years.

Further movements include the movement of the entire Galaxy. Measuring such a movement is also not easy, the distances are too large, and the error in the numbers is still quite large.

Thus, our Galaxy and the Andromeda Galaxy, two massive objects of the Local Group of Galaxies, are gravitationally attracted and move towards each other at a speed of about 100-150 km/sec, with the main component of the speed belonging to our galaxy. The lateral component of the motion is not precisely known, and concerns about a collision are premature. An additional contribution to this movement is made by the massive galaxy M33, located in approximately the same direction as the Andromeda galaxy. In general, the speed of motion of our Galaxy relative to the barycenter Local group of galaxies about 100 km/sec approximately in the Andromeda/Lizard direction (l = 100, b = -4, α = 333, δ = 52), however these data are still very approximate. This is a very modest relative speed: the Galaxy shifts to its own diameter in two to three hundred million years, or, very approximately, in galactic year.

If we measure the speed of the Galaxy relative to distant galaxy clusters, we will see a different picture: both our galaxy and the rest of the galaxies of the Local Group together as a whole are moving in the direction of the large Virgo cluster at approximately 400 km/sec. This movement is also due to gravitational forces.

Background cosmic microwave background radiation defines a certain selected reference frame associated with all baryonic matter in the observable part of the Universe. In a sense, motion relative to this microwave background is motion relative to the Universe as a whole (this motion should not be confused with the recession of galaxies!). This movement can be determined by measuring dipole temperature anisotropy unevenness of cosmic microwave background radiation in different directions. Such measurements showed an unexpected and important thing: all the galaxies in the part of the Universe closest to us, including not only our Local Group, but also the Virgo cluster and other clusters, are moving relative to the background cosmic microwave background radiation at an unexpectedly high speed. For the Local Group of galaxies it is 600-650 km/sec with its apex in the constellation Hydra (α=166, δ=-27). It looks like somewhere in the depths of the Universe there is an as yet undetected huge cluster of many superclusters, attracting matter from our part of the Universe. This hypothetical cluster was named The Great Attractor.

How was the speed of the Local Group of galaxies determined? Of course, in fact, astronomers measured the speed of the Sun relative to the microwave background: it turned out to be ~390 km / s with an apex with coordinates l = 265°, b = 50° (α = 168, δ = -7) on the border of the constellations Leo and Chalice. Then determine the speed of the Sun relative to the galaxies of the Local Group (300 km/s, constellation Lizard). It was no longer difficult to calculate the speed of the Local Group.

Where are we going?

Circadian: observer relative to the center of the Earth	0-465 m/s	East
Annual: Earth relative to the Sun	30 km/sec	perpendicular to the direction of the Sun
Local: The Sun relative to nearby stars	20 km/sec	Hercules
Standard: Sun relative to bright stars	15 km/sec	Hercules
Sun relative to interstellar gas	22-25 km/sec	Ophiuchus
Sun relative to the galactic center	~200 km/sec	Swan
Sun relative to the Local Group of galaxies	300 km/sec	Lizard
Galaxy relative to the Local Group of galaxies	~1 00 km/sec

We all know that the Earth revolves around the Sun. Based on this, a logical question arises: does the Sun itself rotate? And if so, around what? Astronomers received an answer to this question only in the 20th century.


Our star really moves, and if the Earth has two circles of rotation (around the Sun and around its axis), then the Sun has three. Moreover, the entire solar system, along with the planets and other cosmic bodies, is gradually moving away from the center of the galaxy, shifting several million kilometers with each revolution.

What does the Sun move around?

What does the Sun revolve around? It is known that our star is located, the diameter of which is about 30,000 parsecs. A parsec is an astronomical unit of measurement equal to 3.26 light years.

In the central part of the Milky Way there is a relatively small Galactic center with a radius of about 1000 parsecs. Star formation still occurs in it and the core is located, thanks to which our star system once arose.

The distance of the Sun from the Galactic center is 26 thousand light years, that is, it is located closer to the edges of the galaxy. Together with the rest of the stars that make up the Milky Way, the Sun revolves around this center. Its average speed varies from 220 to 240 km per second.

One revolution around the central part of the galaxy takes an average of 200 million years. Over the entire period of its existence, our planet, together with the Sun, orbited the Galactic core only about 30 times.

Why does the Sun revolve around the galaxy?

As with the rotation of the Earth, the exact cause of the movement of the Sun has not been established. According to one version, in the Galactic center there is a certain dark matter(supermassive black hole), which affects both the rotation of stars and their speed. Around this hole there is another hole of smaller mass.

Together, both matters exert a gravitational influence on the stars in the galaxy and force them to move along different trajectories. Other scientists are of the opinion that the movement is due to gravitational forces emanating from the core of the Milky Way.

Like any object, the Sun moves by inertia along a straight path, but the gravity of the Galactic Center attracts it to itself and thereby makes it rotate in a circle.

Does the Sun rotate on its axis?

The rotation of the Sun around its axis is the second circle of its movement. Since it consists of gases, its movement occurs differentially.


In other words, the star rotates faster at its equator, and slower at its poles. Tracking the rotation of the Sun around its axis is quite difficult, so scientists have to navigate by sunspots.

On average, a spot in the region of the solar equator rotates around the axis of the Sun and returns to its original position in 24.47 days. Regions at the poles move around the solar axis every 38 days.

To calculate a specific value, scientists decided to focus on the position 26° from the equator, since approximately in this place it is observed greatest number sunspots. As a result, astronomers came to a single figure, according to which the speed of revolution of the Sun around its own axis is 25.38 days.

What is rotation about a balanced center?

As mentioned above, unlike the Earth, the Sun has three planes of rotation. The first is around the center of the galaxy, the second is around its axis, but the third is the so-called gravitational balanced center. If you explain in simple words, then all the planets revolving around the Sun, although they have much less mass, still attract it a little towards themselves.

As a result of these processes, the Sun's own axis also rotates in space. As it rotates, it describes the radius of the central balancing, within which the Sun rotates. At the same time, the Sun itself also describes its radius. The general picture of this movement is quite clear to astronomers, but its practical component has not been fully studied.


In general, our star is a very complex and multifaceted system, so in the future scientists will have to uncover many more of its secrets and mysteries.

The Earth, together with the planets, revolves around the sun and almost all people on Earth know this. The fact that the Sun revolves around the center of our Milky Way galaxy is already known to a much smaller number of inhabitants of the planet. But that's not all. Our galaxy revolves around the center of the universe. Let's find out about it and watch interesting video footage.

It turns out that the entire solar system moves along with the Sun through the local interstellar cloud (the unchanging plane remains parallel to itself) at a speed of 25 km/s. This movement is directed almost perpendicular to the unchanging plane.

Perhaps here we need to look for explanations for the noticed differences in the structure of the northern and southern hemispheres of the Sun, the stripes and spots of both hemispheres of Jupiter. In any case, this movement determines possible encounters between the solar system and matter scattered in one form or another in interstellar space. The actual motion of the planets in space occurs along elongated helical lines (for example, the “stroke” of the screw of Jupiter’s orbit is 12 times greater than its diameter).

In 226 million years (galactic year), the solar system makes a complete revolution around the center of the galaxy, moving along an almost circular trajectory at a speed of 220 km/s.

Our Sun is part of a huge star system called the Galaxy (also called the Milky Way). Our Galaxy has the shape of a disk, similar to two plates folded at the edges. In its center is the rounded core of the Galaxy.

Our Galaxy - side view

If you look at our Galaxy from above, it looks like a spiral in which stellar matter is concentrated mainly in its branches, called galactic arms. The arms are located in the plane of the Galaxy's disk.

Our Galaxy - view from above

Our Galaxy contains more than 100 billion stars. The diameter of the Galaxy's disk is about 30 thousand parsecs (100,000 light years), and its thickness is about 1000 light years.

The stars within the disk move in circular paths around the center of the Galaxy, just as the planets in the Solar System orbit the Sun. The rotation of the Galaxy occurs clockwise when looking at the Galaxy from its north pole (located in the constellation Coma Berenices). The disk rotation speed is not the same different distances from the center: it decreases as it moves away from it.

The closer to the center of the Galaxy, the higher the density of stars. If we lived on a planet near a star located near the core of the Galaxy, then dozens of stars would be visible in the sky, comparable in brightness to the Moon.

However, the Sun is very far from the center of the Galaxy, one might say - on its outskirts, at a distance of about 26 thousand light years (8.5 thousand parsecs), near the plane of the galaxy. It is located in the Orion Arm, connected to two larger arms - the inner Sagittarius Arm and the outer Perseus Arm.

The Sun moves at a speed of about 220-250 kilometers per second around the center of the Galaxy and makes a complete revolution around its center, according to various estimates, in 220-250 million years. During its existence, the period of revolution of the Sun together with surrounding stars near the center of our star system is called the galactic year. But you need to understand that there is no common period for the Galaxy, since it does not rotate like solid. During its existence, the Sun circled the Galaxy approximately 30 times.

The Sun's revolution around the center of the Galaxy is oscillatory: every 33 million years it crosses the galactic equator, then rises above its plane to a height of 230 light years and descends again to the equator.

Interestingly, the Sun makes a complete revolution around the center of the Galaxy in exactly the same time as the spiral arms. As a result, the Sun does not cross regions of active star formation, in which supernovae often erupt - sources of radiation destructive to life. That is, it is located in the sector of the Galaxy that is most favorable for the origin and maintenance of life.

The solar system is moving through the interstellar medium of our Galaxy much more slowly than previously thought, and no shock wave is forming at its leading edge. This was established by astronomers who analyzed the data collected by the IBEX probe, reports RIA Novosti.

“We can say almost certainly that there is no shock wave in front of the heliosphere (the bubble that limits the Solar System from the interstellar medium), and that its interaction with the interstellar medium is much weaker and more dependent on magnetic fields than previously thought,” the scientists write in the article. published in the journal Science.
Research spacecraft NASA IBEX (Interstellar Boundary Explorer), launched in June 2008, is designed to explore the boundary of the solar system and interstellar space - the heliosphere, located at a distance of approximately 16 billion kilometers from the Sun.

At this distance, the flow of charged solar wind particles and the strength magnetic field The suns weaken so much that they can no longer overcome the pressure of the rarefied interstellar matter and ionized gas. As a result, a “bubble” of the heliosphere is formed, filled inside solar wind, and outside surrounded by interstellar gas.

The Sun's magnetic field deflects the trajectory of charged interstellar particles, but has no effect on the neutral atoms of hydrogen, oxygen and helium, which freely penetrate into the central regions of the Solar System. The detectors of the IBEX satellite “catch” such neutral atoms. Their study allows astronomers to draw conclusions about the features of the solar system's border zone.

A group of scientists from the USA, Germany, Poland and Russia presented a new analysis of data from the IBEX satellite, according to which the speed of the solar system was lower than previously thought. At the same time, as new data indicate, a shock wave does not arise in the front part of the heliosphere.

“The sonic boom that occurs when a jet plane breaks the sound barrier can serve as an terrestrial example for a shock wave. When a plane reaches supersonic speed, the air in front of it can't get out of its way fast enough, resulting in a shock wave,” explains study lead author David McComas, quoted in a press release from Southwestern. research institute(USA).

For about a quarter of a century, scientists believed that the heliosphere was moving through interstellar space at a speed high enough for such a shock wave to form in front of it. However, new IBEX data showed that the solar system is actually moving through a local cloud of interstellar gas at a speed of 23.25 kilometers per second, which is 3.13 kilometers per second slower than previously thought. And this speed is below the limit at which a shock wave occurs.

“Although the shock wave exists in front of the bubbles surrounding many other stars, we found that the interaction of our Sun with environment does not reach the threshold at which a shock wave is generated,” McComas said.

Previously, the IBEX probe was engaged in mapping the boundary of the heliosphere and discovered a mysterious strip on the heliosphere with increased fluxes of energetic particles, which surrounded the “bubble” of the heliosphere. Also, with the help of IBEX, it was established that the speed of movement of the Solar system over the past 15 years, for inexplicable reasons, has decreased by more than 10%.

The universe is spinning like a spinning top. Astronomers have discovered traces of the rotation of the universe.

Until now, most researchers were inclined to believe that our universe is static. Or if it moves, it’s only a little. Imagine the surprise of a team of scientists from the University of Michigan (USA), led by Professor Michael Longo, when they discovered clear traces of the rotation of our universe in space. It turns out that from the very beginning, even during the Big Bang, when the Universe was just born, it was already rotating. It was as if someone had launched it like a spinning top. And she is still spinning and spinning.

The research was carried out within international project Sloan Digital Sky Survey. And scientists discovered this phenomenon by cataloging the direction of rotation of about 16,000 spiral galaxies from the north pole of the Milky Way. At first, scientists tried to find evidence that the Universe has the properties of mirror symmetry. In this case, they reasoned, the number of galaxies that rotate clockwise and those that “spin” in opposite direction, would be the same, reports pravda.ru.

But it turned out that towards north pole Among the Milky Way spiral galaxies, counterclockwise rotation predominates, that is, they are oriented to the right. This trend is visible even at a distance of more than 600 million light years.

The symmetry violation is small, only about seven percent, but the probability that this is such a cosmic accident is somewhere around one in a million,” commented Professor Longo. “Our results are very important because they seem to contradict the almost universal belief that if you take a large enough scale, the Universe will be isotropic, that is, it will not have a clear direction.

According to experts, a symmetrical and isotropic Universe should have arisen from a spherically symmetrical explosion, which should have been shaped like a basketball. However, if at birth the Universe rotated around its axis in a certain direction, then the galaxies would maintain this direction of rotation. But, since they rotate in different directions, it follows that the Big Bang had a diversified direction. However, the Universe is most likely still spinning.

In general, astrophysicists had previously guessed about the violation of symmetry and isotropy. Their guesses were based on observations of other giant anomalies. These include traces of cosmic strings - incredibly extended defects of space-time of zero thickness, hypothetically born in the first moments after the Big Bang. The appearance of “bruises” on the body of the Universe - the so-called imprints from its past collisions with other universes. And also the movement of the “Dark Stream” - a huge stream of galactic clusters rushing at enormous speed in one direction.

You sit, stand or lie reading this article and do not feel that the Earth is spinning on its axis at a breakneck speed - approximately 1,700 km/h at the equator. However, the rotation speed does not seem that fast when converted to km/s. The result is 0.5 km/s - a barely noticeable blip on the radar, in comparison with other speeds around us.

Just like other planets in the solar system, the Earth revolves around the Sun. And in order to stay in its orbit, it moves at a speed of 30 km/s. Venus and Mercury, which are closer to the Sun, move faster, Mars, whose orbit passes behind the Earth’s orbit, moves much slower.

But even the Sun does not stand in one place. Our Milky Way galaxy is huge, massive and also mobile! All stars, planets, gas clouds, dust particles, black holes, dark matter - all of this moves relative to a common center of mass.

According to scientists, the Sun is located at a distance of 25,000 light years from the center of our galaxy and moves in an elliptical orbit, making a full revolution every 220–250 million years. It turns out that the speed of the Sun is about 200–220 km/s, which is hundreds of times higher than the speed of the Earth around its axis and tens of times higher than the speed of its movement around the Sun. This is what the movement of our solar system looks like.

Is the galaxy stationary? Not again. Gigantic space objects have a large mass, and therefore create strong gravitational fields. Give the Universe some time (and we've had it for about 13.8 billion years), and everything will start moving in the direction of greatest gravity. That is why the Universe is not homogeneous, but consists of galaxies and groups of galaxies.

What does this mean for us?

This means that the Milky Way is pulled towards it by other galaxies and groups of galaxies located nearby. This means that massive objects dominate the process. And this means that not only our galaxy, but also everyone around us is influenced by these “tractors”. We are getting closer to understanding what happens to us in outer space, but we still lack facts, for example:

• what were the initial conditions under which the Universe began;
• how the different masses in the galaxy move and change over time;
• how the Milky Way and surrounding galaxies and clusters were formed;
• and how it is happening now.

However, there is a trick that will help us figure it out.

The Universe is filled with relict radiation with a temperature of 2.725 K, which has been preserved since the Big Bang. Here and there there are tiny deviations - about 100 μK, but the overall temperature background is constant.

This is because the Universe was formed by the Big Bang 13.8 billion years ago and is still expanding and cooling.

380,000 years after the Big Bang, the Universe cooled to such a temperature that the formation of hydrogen atoms became possible. Before this, photons constantly interacted with other plasma particles: they collided with them and exchanged energy. As the Universe cooled, there were fewer charged particles and more space between them. Photons were able to move freely in space. CMB radiation is photons that were emitted by the plasma towards the future location of the Earth, but escaped scattering because recombination had already begun. They reach the Earth through the space of the Universe, which continues to expand.

You can “see” this radiation yourself. The interference that occurs on a blank TV channel if you use a simple antenna that looks like a rabbit's ears is 1% caused by the CMB.

Still, the temperature of the relict background is not the same in all directions. According to the results of research by the Planck mission, temperatures differ slightly in opposite hemispheres celestial sphere: it is slightly higher in parts of the sky south of the ecliptic - about 2.728 K, and lower in the other half - about 2.722 K.

Map of the microwave background made with the Planck telescope.

This difference is almost 100 times larger than other observed temperature variations in the CMB, and is misleading. Why is this happening? The answer is obvious - this difference is not due to fluctuations in the cosmic microwave background radiation, it appears because there is movement!

When you approach a light source or it approaches you, the spectral lines in the source's spectrum shift towards short waves (violet shift), when you move away from it or it moves away from you, the spectral lines shift towards long waves (red shift).

CMB radiation cannot be more or less energetic, which means we are moving through space. The Doppler effect helps determine that our Solar System is moving relative to the CMB at a speed of 368 ± 2 km/s, and the local group of galaxies, including the Milky Way, the Andromeda Galaxy and the Triangulum Galaxy, is moving at a speed of 627 ± 22 km/s relative to the CMB. These are the so-called peculiar velocities of galaxies, which amount to several hundred km/s. In addition to them, there are also cosmological velocities due to the expansion of the Universe and calculated according to Hubble’s law.

Thanks to residual radiation from the Big Bang, we can observe that everything in the Universe is constantly moving and changing. And our galaxy is only part of this process.

Any person, even lying on the couch or sitting near the computer, is in constant motion. This continuous movement in outer space has a variety of directions and enormous speeds. First of all, the Earth moves around its axis. In addition, the planet rotates around the Sun. But that's not all. We cover much more impressive distances together with the Solar System.

The Sun is one of the stars located in the plane of the Milky Way, or simply the Galaxy. It is distant from the center by 8 kpc, and the distance from the plane of the Galaxy is 25 pc. The stellar density in our region of the Galaxy is approximately 0.12 stars per 1 pc3. The position of the Solar System is not constant: it is in constant motion relative to nearby stars, interstellar gas, and finally, around the center of the Milky Way. The movement of the Solar System in the Galaxy was first noticed by William Herschel.

Moving relative to nearby stars

The speed of movement of the Sun to the border of the constellations Hercules and Lyra is 4 a.s. per year, or 20 km/s. The velocity vector is directed towards the so-called apex - the point towards which the movement of other nearby stars is also directed. Directions of star velocities, incl. The suns intersect at a point opposite the apex, called the antiapex.

Moving relative to visible stars

The movement of the Sun relative to bright stars that can be seen without a telescope. This is an indicator of the standard movement of the Sun. The speed of such movement is 3 AU. per year or 15 km/s.

Moving relative to interstellar space

In relation to interstellar space, the Solar system is already moving faster, the speed is 22-25 km/s. At the same time, under the influence of the “interstellar wind”, which “blows” from the southern region of the Galaxy, the apex shifts to the constellation Ophiuchus. The shift is estimated to be approximately 50.

Navigating around the center of the Milky Way

The solar system is in motion relative to the center of our Galaxy. It moves towards the constellation Cygnus. The speed is about 40 AU. per year, or 200 km/s. For full turn 220 million years are needed. It is impossible to determine the exact speed, because the apex (the center of the Galaxy) is hidden from us behind dense clouds of interstellar dust. The apex shifts by 1.5° every million years, and completes a full circle in 250 million years, or 1 galactic year.

Journey to the edge of the Milky Way

Movement of the Galaxy in outer space

Our Galaxy also does not stand still, but is approaching the Andromeda Galaxy at a speed of 100-150 km/s. A group of galaxies, which includes the Milky Way, is moving towards the large Virgo cluster at a speed of 400 km/s. It is difficult to imagine, and even more difficult to calculate, how far we travel every second. These distances are enormous, and the errors in such calculations are still quite large.