The movement of the stars and the solar system. How the solar system moves First established the movement of the solar system

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 tremendous speeds. First of all, the Earth moves around its axis. In addition, the planet revolves around the sun. But that's not all. Much more impressive distances we overcome together with the solar system.

The sun is one of the stars in the plane of the Milky Way, or simply the Galaxy. It is 8 kpc away from the center, 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.

Movement 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 - a point to which the movement of other nearby stars is also directed. Directions of velocities of stars, incl. The suns intersect at the point opposite to the apex, called the anti-apex.

Moving relative to visible stars

Separately, the movement of the Sun in relation to bright stars that can be seen without a telescope is measured. 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.

Movement 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 "blowing" from the southern region of the Galaxy, the apex shifts to the constellation Ophiuchus. The shift is estimated at about 50.

Moving 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. It takes 220 million years for a complete revolution. 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 1.5° every million years, and completes a full circle in 250 million years, or 1 "galactic year.

Surely, many of you have seen a gif or watched a video showing the movement of the solar system.

We check scientists

Astronomy says that the angle between the planes of the ecliptic and the galaxy is 63°.

But the figure itself is boring, and even now, when on the sidelines of science adherents of the flat Earth, I want to have a simple and clear illustration. Let's think about how we can see the planes of the Galaxy and the ecliptic in the sky, preferably with the naked eye and without moving far from the city? The plane of the Galaxy is the Milky Way, but now, with an abundance of light pollution, it is not so easy to see it. Is there any line approximately close to the plane of the Galaxy? Yes, it is the constellation Cygnus. It is clearly visible even in the city, and it is easy to find it, relying on the bright stars: Deneb (alpha Cygnus), Vega (alpha Lyra) and Altair (alpha Eagle). The "torso" of Cygnus approximately coincides with the galactic plane.

Okay, we have one plane. But how to get a visual line of the ecliptic? Let's think, what is the ecliptic in general? According to the modern strict definition, the ecliptic is a section of the celestial sphere by the plane of the orbit of the barycenter (center of mass) of the Earth-Moon. On the average, the Sun moves along the ecliptic, but we do not have two Suns, according to which it is convenient to draw a line, and the Cygnus constellation will not be visible in sunlight. But if we remember that the planets of the solar system also move approximately in the same plane, then it turns out that the parade of planets will just roughly show us the plane of the ecliptic. And now in the morning sky you can just see Mars, Jupiter and Saturn.

As a result, in the coming weeks, in the morning before sunrise, it will be possible to very clearly see the following picture:

Which, surprisingly, is in perfect agreement with astronomy textbooks.

And it's better to draw a gif like this:

The question can cause the relative position of the planes. Are we flying<-/ или же <-\ (если смотреть с внешней стороны Галактики, северный полюс вверху)? Астрономия говорит, что Солнечная система движется относительно ближайших звезд в направлении созвездия Геркулеса, в точку, расположенную недалеко от Веги и Альбирео (бета Лебедя), то есть правильное положение <-/.

But this fact, alas, cannot be verified “on the fingers”, because, even if they did it two hundred and thirty-five years ago, they used the results of many years of astronomical observations and mathematics.

Receding stars

How can you generally determine where the solar system is moving relative to nearby stars? If we can record the movement of a star across the celestial sphere for decades, then the direction of movement of several stars will tell us where we are moving relative to them. Let's call the point to which we are moving, the apex. Stars that are not far from it, as well as from the opposite point (anti-apex), will move weakly, because they are flying towards us or away from us. And the farther the star is from the apex and anti-apex, the greater will be its own motion. Imagine that you are driving down the road. Traffic lights at intersections in front and behind will not shift much to the sides. But the lampposts along the road will flicker (have a large own movement) outside the window.

The gif shows the movement of Barnard's star, which has the largest proper motion. Already in the 18th century, astronomers had records of the position of stars over an interval of 40-50 years, which made it possible to determine the direction of motion of slower stars. Then the English astronomer William Herschel took the star catalogs and, without approaching the telescope, began to calculate. Already the first calculations according to Mayer's catalog showed that the stars do not move randomly, and the apex can be determined.

Source: Hoskin, M. Herschel's Determination of the Solar Apex, Journal for the History of Astronomy, Vol. 11, P. 153, 1980

And with the data of the Lalande catalog, the area was significantly reduced.

From there

Then normal scientific work went on - data clarification, calculations, disputes, but Herschel used the correct principle and was only ten degrees wrong. Information is still being collected, for example, only thirty years ago, the speed of movement was reduced from 20 to 13 km / s. Important: this speed should not be confused with the speed of the solar system and other nearby stars relative to the center of the Galaxy, which is approximately 220 km/s.

Even further

Well, since we mentioned the speed of movement relative to the center of the Galaxy, it is necessary to understand here as well. The galactic north pole is chosen in the same way as the earth's - arbitrarily by agreement. It is located near the star Arcturus (alpha Bootes), approximately up in the direction of the wing of the constellation Cygnus. But in general, the projection of the constellations on the map of the Galaxy looks like this:

Those. The solar system moves relative to the center of the Galaxy in the direction of the constellation Cygnus, and relative to the local stars in the direction of the constellation Hercules, at an angle of 63 ° to the galactic plane,<-/, если смотреть с внешней стороны Галактики, северный полюс сверху.

space tail

But the comparison of the solar system with a comet in the video is absolutely correct. NASA's IBEX was specifically designed to determine the interaction between the boundary of the solar system and interstellar space. And according to him there is a tail.

NASA illustration

For other stars, we can see the astrospheres (stellar wind bubbles) directly.

Photo by NASA

Positive in the end

Concluding the conversation, it is worth noting a very positive story. DJSadhu, who created the original video in 2012, originally promoted something unscientific. But, thanks to the viral distribution of the clip, he talked with real astronomers (astrophysicist Rhys Tailor is very positive about dialogue) and, three years later, made a new, much more realistic video without anti-scientific constructions.

https://geektimes.ru/post/298077

Surely, many of you have seen a gif or watched a video showing the movement of the solar system.

Video clip, released in 2012, went viral and made a lot of noise. I came across him shortly after his appearance, when I knew much less about space than I do now. And most of all I was confused by the perpendicularity of the plane of the orbits of the planets to the direction of motion. It's not that it's impossible, but the Solar System can move at any angle to the plane of the Galaxy. You ask, why remember long-forgotten stories? The fact is that right now, with the desire and the presence of good weather, everyone can see in the sky the real angle between the planes of the ecliptic and the Galaxy.

We check scientists

Astronomy says that the angle between the planes of the ecliptic and the galaxy is 63°.

But the figure itself is boring, and even now, when adherents of the flat Earth arrange a coven on the sidelines of science, I want to have a simple and visual illustration. Let's think about how we can see the planes of the Galaxy and the ecliptic in the sky, preferably with the naked eye and without moving far from the city? The plane of the Galaxy is the Milky Way, but now, with an abundance of light pollution, it is not so easy to see it. Is there any line approximately close to the plane of the Galaxy? Yes, it is the constellation Cygnus. It is clearly visible even in the city, and it is easy to find it, relying on the bright stars: Deneb (alpha Cygnus), Vega (alpha Lyra) and Altair (alpha Eagle). The "torso" of Cygnus approximately coincides with the galactic plane.

As a result, in the coming weeks, in the morning before sunrise, it will be possible to very clearly see the following picture:

Which, surprisingly, is in perfect agreement with astronomy textbooks.

And it's better to draw a gif like this:

Source: astronomer Rhys Taylor website rhysy.net

Receding stars

Source: Hoskin, M. Herschel's Determination of the Solar Apex, Journal for the History of Astronomy, Vol. 11, P. 153, 1980

And with the data of the Lalande catalog, the area was significantly reduced.

From there

Even further

space tail

The movement of the stars

<>moving in pro

wandering. However, these movements occur at such distances from us that only after many millennia, changes in the arrangement of stars in the constellations can become sufficiently noticeable, even with the most accurate observations. Many stars move in space in such a way that they either get closer to us or move away from us: they move along the line of sight. This movement cannot be detected by observing the positions of the stars. Here again, spectral analysis comes to the rescue: the shift of lines in the spectrum of a particular star to the red or violet end of the spectrum shows whether the star is moving away from us or towards us. The magnitude of this shift is used to calculate the velocities of movement along the line of sight. Back in the 18th century astronomers have noticed that the stars in the region lying near the border of the constellations Hercules and Lyra seem to part in different directions from one point in the sky. In the opposite area - in the constellation Canis Major - the stars seem to be approaching each other. This shift occurs because our solar system itself is moving relative to these stars, approaching some and moving away from others. The motion of the solar system relative to the stars surrounding it, first established in 1783 by V. Herschel, occurs at a speed of about 20 km / s in the direction of the constellations Lyra and Hercules.

For many centuries, astronomers called the stars "fixed", distinguishing them by this name from the planets that move, "wander" against the background of stars. Accurate measurements of the apparent positions of the stars and a comparison of these positions with observations made in ancient times led the English astronomer Halley to the conclusion that the stars move,<>moving in space. However, these movements occur at such distances from us that only after many millennia, changes in the arrangement of stars in the constellations can become sufficiently noticeable, even with the most accurate observations. Many stars move in space in such a way that they either get closer to us or move away from us: they move along the line of sight. This movement cannot be detected by observing the positions of the stars. Here again, spectral analysis comes to the rescue: the shift of lines in the spectrum of a particular star to the red or violet end of the spectrum shows whether the star is moving away from us or towards us. The magnitude of this shift is used to calculate the velocities of movement along the line of sight. Back in the 18th century astronomers have noticed that the stars in the region lying near the border of the constellations Hercules and Lyra seem to part in different directions from one point in the sky. In the opposite area - in the constellation Canis Major - the stars seem to be approaching each other. This shift occurs because our solar system itself is moving relative to these stars, approaching some and moving away from others. The motion of the solar system relative to the stars surrounding it, first established in 1783 by V. Herschel, occurs at a speed of about 20 km / s in the direction of the constellations Lyra and Hercules.

Luminosity

For a long time, astronomers believed that the difference in the apparent brilliance of stars is due only to the distance to them: the farther the star, the less bright it should appear. But when distances to stars became known, astronomers found that sometimes more distant stars have a greater apparent brilliance. This means that the apparent brilliance of stars depends not only on their distance, but also on the actual strength of their light, that is, on their luminosity. The luminosity of a star depends on the size of the surface of the stars and on its temperature. The luminosity of a star expresses its true luminous intensity compared to the luminous intensity of the Sun. For example, when they say that the luminosity of Sirius is 17, this means that the true strength of its light is 17 times greater than the light of the Sun.

Determining the luminosity of stars, astronomers have found that many stars are thousands of times brighter than the Sun, for example, the luminosity of Deneb (alpha Cygnus) is 9400. Among the stars there are those that emit hundreds of thousands of times more light than the Sun. An example is the star designated by the letter S in the constellation Dorado. It shines 1,000,000 times brighter than the Sun. Other stars have the same or almost the same luminosity as our Sun, for example, Altair (Alpha Eagle) -8. There are stars whose luminosity is expressed in thousandths, that is, their luminous intensity is hundreds of times less than that of the Sun.

Color, temperature and composition of stars

The stars have different colors. For example, Vega and Deneb are white, Capella is yellowish, and Betelgeuse is reddish. The lower the temperature of a star, the redder it is. The temperature of white stars reaches 30,000 and even 100,000 degrees; the temperature of yellow stars is about 6000 degrees, and the temperature of red stars is 3000 degrees and below.

Stars consist of hot gaseous substances: hydrogen, helium, iron, sodium, carbon, oxygen and others.

Cluster of stars

The stars in the vast expanse of the Galaxy are distributed fairly evenly. But some of them still accumulate in certain places. Of course, even there the distances between the stars are still very large. But because of the gigantic distances, such closely spaced stars look like a star cluster. That is why they are called so. The most famous of the star clusters are the Pleiades in the constellation Taurus. With the naked eye in the Pleiades, 6-7 stars can be distinguished, located very close to each other. With a telescope, you can see more than a hundred of them in a small area. This is one of the clusters in which the stars form a more or less isolated system, connected by a common movement in space. The diameter of this star cluster is about 50 light years. But even with the apparent closeness of the stars in this cluster, they are actually quite far from each other. In the same constellation, surrounding its main - the brightest - reddish star Al-debaran, there is another, more scattered star cluster - Hyades.

Some star clusters in weak telescopes look like hazy, blurry spots. In stronger telescopes, these spots, especially towards the edges, break up into individual stars. Large telescopes make it possible to establish that these are especially close star clusters that have a spherical shape. Therefore, such clusters are called globular. More than a hundred globular star clusters are now known. All of them are very far from us. Each of them consists of hundreds of thousands of stars.

The question of what constitutes the world of the stars seems to be one of the first questions that mankind faced at the dawn of civilization. Any person contemplating the starry sky, involuntarily links the brightest stars together into the simplest figures - squares, triangles, crosses, becoming the unwitting creator of his own map of the starry sky. Our ancestors went the same way, dividing the starry sky into clearly distinguishable combinations of stars, called constellations. In ancient cultures, we find references to the first constellations identified with symbols of the gods or myths, which have come down to us in the form of poetic names - the constellation of Orion, the constellation of the Hounds, the constellation of Andromeda, etc. These names, as it were, symbolized the ideas of our ancestors about the eternity and immutability of the universe, the constancy and immutability of the harmony of the cosmos.

Stars in antiquity were considered fixed relative to each other. However, in the XVIII century. Sirius was found to move very slowly across the sky. It is noticeable only when comparing accurate measurements of its position, made with a time interval of decades.

The proper motion of a star is its apparent angular displacement across the sky in one year. It is expressed in fractions of a second of arc per year.

Only Barnard's star passes an arc in a year which in 200 years will be 0.5 °, or the apparent diameter of the Moon. For this, Barnard's star was called "flying". But if the distance to a star is unknown, then its own motion says little about its true speed.

For example, the paths traveled by the stars in a year (Fig. 98) may be different: and the proper motions corresponding to them are the same.

2. Components of the spatial velocity of stars.

The speed of a star in space can be represented as a vector sum of two components, one of which is directed along the line of sight, the other is perpendicular to it. The first component is the radial, the second is the tangential velocity. The proper motion of a star is determined only by its tangential velocity and does not depend on the radial velocity. To calculate the tangential velocity in kilometers per second, it is necessary to multiply, expressed in radians per year, by the distance to the star, expressed in kilometers,

Rice. 98. Proper motion ray tangential and total spatial speed of the star.

Rice. 99. Change in the apparent location of the bright stars of the constellation Ursa Major due to their own movements: from above - 50 thousand years ago; in the middle - at the present time; below - after 50 thousand years.

and divide by the number of seconds in a year. But since in practice it is always determined in seconds of arc, in parsecs, then for calculating in kilometers per second the formula is obtained:

If the radial velocity of a star is also determined by the spectrum, then its spatial velocity V will be equal to:

The speeds of stars relative to the Sun (or Earth) are usually tens of kilometers per second.

The proper motions of stars are determined by comparing photographs of a selected area of the sky taken with the same telescope over a period of time measured in years or even decades. Due to the fact that the star is moving, its position against the background of more distant stars changes slightly during this time. The displacement of a star in photographs is measured using special microscopes. Such a shift can only be estimated for relatively nearby stars.

Unlike tangential velocity, radial velocity can be measured even if the star is very far away, but its brightness is sufficient to obtain a spectrogram.

Stars that are close to each other in the sky can be located far apart in space and move at different speeds. Therefore, after millennia, the appearance of the constellations must change greatly due to the proper motions of the stars (Fig. 99).

3. Movement of the solar system.

At the beginning of the XIX century. W. Herschel

established from the proper motions of a few nearby stars that in relation to them the solar system moves in the direction of the constellations Lyra and Hercules. The direction in which the solar system is moving is called the apex of motion. Subsequently, when they began to determine the radial velocities of stars from the spectra, Herschel's conclusion was confirmed. In the direction of the apex, the stars approach us on average at a speed of 20 km/s, and in the opposite direction they move away from us at the same speed on average.

So, the solar system is moving in the direction of the constellations Lyra and Hercules at a speed of 20 km / s with respect to neighboring stars. It is meaningless to ask the question of when we will reach the constellation Lyra, since the constellation is not a spatially limited formation. Some stars, which we now attribute to the constellation Lyra, we pass earlier (at a great distance from them), others will always remain almost as far from us as they are now.

(see scan)

4. If a star (see problem 1) is approaching us at a speed of 100 km/s, how will its brightness change in 100 years?

4. Rotation of the Galaxy.

All the stars of the Galaxy revolve around its center. The angular velocity of revolution of stars in the inner region of the Galaxy (almost to the Sun) is approximately the same, while its outer parts rotate more slowly. In this way, the rotation of stars in the Galaxy differs from the rotation of planets in the Solar System, where both angular and linear velocities decrease rapidly with increasing orbital radius. This difference is due to the fact that the core of the Galaxy does not dominate in its mass, like the Sun in the solar system.

The solar system makes a complete revolution around the center of the Galaxy in about 200 million lats at a speed of 250 km/s.