Undoubtedly main star in winter. This brightest diamond literally catches the eye, it is so bright! However, people who are far from astronomy are still more surprises star behavior: Sirius usually shimmers strongly and shimmers with all the colors of the rainbow, so quickly that you can’t even tell right away what color it is. Why is that?

Before indulging in explanations, let us assure you that they flicker all Stars not just Sirius. (If you see a very bright, but practically non-flickering star in the sky, then most likely it is a planet - Venus or Jupiter.) Those stars that are closer to the horizon twinkle more strongly; those at the zenith, on the contrary, flicker much weaker.

The same applies to the rapid change of colors: not only Sirius shows a similar effect, but in the case of this star, it is especially striking - simply because Sirius is the brightest star in the night sky and attracts the highest priority. And, frankly, in our latitudes, Sirius flickers almost always, because it does not rise high above the horizon.

Behind all these phenomena is earth atmosphere. The fact is that air envelope around our planet is not at all homogeneous. At different heights, the air has different temperature, which leads to the formation of air currents, vortices, Hadley cells and other formations. Air cells have different densities due to different temperatures, which means they refract and deflect the light passing through them differently. For simplicity, such atmospheric cells can be compared to very weak lenses capable of focusing and deflecting light rays passing through them.

Stars twinkle much more strongly near the horizon than at the zenith, as their light travels through more air. Picture: Bob King

For this reason, even on the most calm and transparent night, the light of the stars reaches us at least a little, but distorted. Passing through the restless atmosphere, the light of the star will either be focused and completely fall into the eye (and at this moment we will see it bright), then for the most part deviate to the side (and then it will fade). This rapid fluctuation in brightness is what we call flickering.

By the way, light bending can be seen directly when observing Sirius through a telescope with big increase. Not only will the star look in the eyepiece as an unfocused spot of light, but it will also dance from side to side, as if alive!

But the most striking consequence of this effect is the fact that a star can disappear completely for a moment! Watch Sirius closely for a while on a night when it flickers intensely, and you are almost guaranteed to catch this moment!

The second moment is the transfusion of Sirius with all the colors of the rainbow. And here it's all about atmospheric circulation, because light different lengths Waves curve differently! It turns out that the air behaves like a prism, decomposing the star's light into a spectrum! But then one color comes to us, then another, then a third. If you photograph Sirius in succession with very short exposures, then we will see literally the entire palette of colors in the photographs!

A series of snapshots of Sirius illustrating the chaotic color change of the star. Sirius appears as circles in the pictures because it was intentionally out of focus in order to show the color more clearly. A photo: Bob King

If you shoot a star with a longer exposure, but at the same time move the camera from side to side so that the star constantly moves in the lens, then Sirius will appear in the photograph as a beautiful multi-colored curve.

Scintillations (flicker) of Sirius, filmed through a shaking camera. A photo: www.cosmicriver.net

In fact, the color of Sirius is white. it hot star, whose surface temperature is almost twice the temperature of the surface of the Sun! AT southern countries, where Sirius rises to the zenith and does not flicker so much, White color the stars are very clear.

Have you ever noticed how the straight lines on the bottom of a tiled pool seem to sway from side to side? This phenomenon occurs because the water in the pool refracts the rays of light reflected from the bottom of the pool. Likewise, stars twinkle due to turbulence in the Earth's atmosphere. must pass through several kilometers of the earth's atmosphere before reaching the observer's eye. Here the Earth's atmosphere acts like water in a pool.

A lot depends on air.

Why do stars twinkle? Yes, because a lot depends on the temperature of the air. It usually decreases by 6.5°C with every kilometer we go up. That is why it is cold in the mountains. The Earth's atmosphere consists of several "layers". Each layer has a different temperature and density. Warm air refracts light rays less, while cool air distorts more because in warm air, air molecules are farther apart, producing less light scattering.

Our atmosphere is saturated with very turbulent currents and whirlwinds of air. These circumstances, together with temperature changes in the atmosphere, act as lenses and prisms that sway the incoming light from the star from side to side, several times a second. This causes a change in brightness and location.

The higher the position for stargazing, the better.

Because of this effect, observatories for studying stars are located on mountain peaks. The reason for this is that the higher you go, the thinner the layers of air and the less causing the shimmer effect. Scientists are conducting experiments to compensate for the flickering effect by adapting the optics of telescopes. As a result, astronomers will soon be able to see a much clearer image of the stars here on earth.

Have you noticed that Stars closer to the horizon twinkle more this is because the atmosphere between you and the stars above the horizon is richer than between you and a star directly overhead.

The telescope was launched into outer space because there is no atmosphere, which allowed scientists to see clear images of the universe.

Planets don't twinkle like stars. This is because planets shine by reflected light and are closer than stars, causing less refraction. In fact, this is a good way to find out if the object you see in the sky is a planet or a star. For a planet, light that bounces off a cluster of dots on the planet's disk and flickers and changes colors. However, the twinkling of one part of the planet is complemented by another shimmering part of the planet. Thus, the planet seems to glow constantly, while the stars around it twinkle in the sky.

The night starry sky always evokes special feelings, often all earthly affairs become unimportant, and a person begins to feel like a small particle vast universe, part of something bigger than just the planet Earth.

Why do the stars twinkle? Probably many people have asked themselves this question. An incredibly beautiful sight, especially after rain, when the stars shimmer with all the colors of the rainbow. People do not always know how to answer such a seemingly childish question.

A simple answer to a simple question

Star twinkling is caused directly by vibrations in the air. Due to the heterogeneity of the Earth's atmosphere, air masses moving at different speeds, while real currents and flows are formed, different in temperature properties, density and other parameters. Therefore, starlight passing through the atmosphere can be refracted by the most different ways. So there is a semblance of this mysterious flicker.

twinkling star

A twinkling star in the sky is like a twinkle big city if you look at it from afar. And if at the same time the air is saturated with moisture, then the glow will change its trajectory and refract, shimmering with all the colors of the rainbow. The answer to the question of why stars twinkle turns out to be so simple. As the star begins to approach the horizon, the refraction occurs even more intensely due to the thickness of the air, thereby making the twinkling more distinct.

Can planets twinkle?

Stars differ from planets in a huge number physical characteristics, it is not surprising that these inhabitants of space shine in different ways. Even on a beautiful night with many twinkling stars, you can clearly distinguish the light emanating from the planets. solar system. Their light can be described as even, constant. Like the Moon or the Sun, they do not flicker. This can be seen even without an ultra-precise microscope.

Why is this happening? If we take into account the factors that the light of the stars, like the light of the planet, must be refracted in the layers of the atmosphere, we can conclude that the stars twinkle pointwise, the planet does the same, but due to the fact that it has many such points, the illusion of an even Sveta. It's all about quantity.

Such different stars

If you look at the stars with the naked eye, they all seem almost the same, different only in brightness. But this is far from the case, if you look more closely, you can distinguish the stars even by color. This applies to the largest bright stars. For example, the stars Arcturus and Aldebaran orange color, while Betelgeuse and Antares are red. Sirius and Vega are called white, Spica and Regulus are white with a blue tint. There are even yellow giants Capella and

Astronomers associate the color of stars with a parameter such as temperature. Relatively cold are red stars with a surface temperature of up to 4 thousand degrees, the hottest are white-blue, reaching an incredible temperature of 10-30 thousand degrees Celsius! It becomes quite clear why the stars twinkle, with such temperature data, they are capable of much.

Why do stars twinkle and do they twinkle at all? The answer to this question depends on how you look at it. If this process is identified with refraction, then it can be called flickering. But, as you know, the stars themselves do not glow, just such an impression is formed by the viewer who observes this interesting phenomenon from the Earth. If you contemplate this picture from space, then there will be no flicker. According to the astronauts, the stars shine brightly, evenly, and they wink only at those observers who have remained on Earth.

Even without being an astronomer, you can easily distinguish stars from planets in the night sky. The planets shine with an even light and from the Earth they look like tiny circles with even edges.


The stars do not give such a glow - they seem to flicker and shimmer, and they can take on different shades. Why is this happening?

Starlight and Earth's Atmosphere

Visible human eye stellar twinkling is not a property of stars, but a feature visual perception from Earth. You probably noticed that the twinkling of stars is especially colorful in frosty nights Or right after the rain?

The fact is that the reason for the twinkling of stars is the atmosphere. Stars emit light that passes through the layers of the atmosphere on its way to the Earth, and it is known to be inhomogeneous.

Rays of starlight need to penetrate regions of the atmosphere with different densities and temperatures, and this directly affects the refraction of light rays. Plots of gas layers different density make this refraction multidirectional.


Do not forget that air masses are mobile: warm streams rise up, cold ones sink to the surface of the Earth. Air refracts light differently depending on its temperature. When the light of a star passes from the atmosphere high density to an area with a lower density and vice versa, it becomes flickering. The very brightness of the stars also changes: they dim, then shine again.

Scientists call this process scintillation. In addition, the process of light emission from stars is affected by turbulent eddies that move in different directions at various heights.

Different parts of the atmosphere act on a beam of light like lenses with a constantly changing curvature. The rays, passing through these peculiar "lenses", are either scattered or refocused. This is accompanied by a scattering of color, so stars low above the horizon can change their hue.

The higher from the Earth, the less noticeable is the stellar twinkling - the layer of the atmosphere becomes thinner, the optical effect on the rays of light decreases. It is for this reason that scientific observatories are usually set up as high as possible in the mountains - from there it is easier to observe the stars without being distracted by strong flicker.

There is no atmosphere in space, and, according to the astronauts and the available images from space telescopes, the stars there shine even and calm light.

Why don't the planets twinkle?

Planets shine with uniform light primarily because they are located much closer to the surface of the Earth than stars. We see the stars as twinkling points, while the planets are perceived by the eye as small disks, which, due to their brightness, seem to be absolutely round. The fact is that planets by their nature differ from stars in that they do not radiate own light, but reflect an outsider.

From some parts of the planet, light is reflected more intensely, from others - weaker, and after just a second, the intensity of the reflection changes. At the same time, the average intensity of the reflection of light rays from the planet remains unchanged, and from the human point of view, the light from the celestial body remains even and calm.

In other words, the planets also twinkle, but with a different, constantly changing intensity in different points, and these changes in the brightness of the reflection at different times complement each other. The total reflection of light from the planet remains constant.

Most bright planets The solar system visible from Earth to the naked eye is Venus and Jupiter. Venus is clearly visible in the morning and evening sky, against the backdrop of dawn; it glows with a steady yellow light. Venus is the third brightest in the sky (when viewed from Earth) and the Moon. Jupiter's brilliance is slightly fainter, and this planet also has a yellow tint.


AT recent decades Mars is very prominent in the sky from time to time. Mercury, the planet closest to the Sun, is also quite bright, but it can be recognized only with certain knowledge.

Due to the fact that Mercury is as close as possible to the Sun, it hides in its rays, and it is easy to see the planet only when it moves away from the star at a certain distance. This usually happens at dawn or dusk.

There are many interesting things in the world. The twinkling of stars is one of the most amazing phenomena. How many different beliefs are connected with this phenomenon! The unknown always scares and attracts at the same time. What is the nature of such a phenomenon?

Influence of the atmosphere

Astronomers have done interesting discovery: the twinkling of stars has nothing to do with their changes. Then why do the stars twinkle in the night sky? It's all about the atmospheric movement of cold and hot air flows. Where warm layers pass over cold ones, air vortices form there. Under the influence of these vortices, the light rays are distorted. So the light rays are bent, changing the apparent position of the stars.

An interesting fact is that the stars do not twinkle at all. Such a vision is created on earth. The eyes of observers perceive the light coming from the star as it passes through the atmosphere. Therefore, the question of why the stars twinkle can be answered that the stars do not twinkle, and the phenomenon that we observe on earth is a distortion of the light that has traveled from the star through the atmospheric layers of air. If such air movements did not occur, then flicker would not be observed, even from the very distant star in space.

scientific explanation

If we reveal in more detail the question of why stars twinkle, then it is worth noting that this process is observed when light from a star passes from a denser atmospheric layer to a less dense one. In addition, as mentioned above, these layers are constantly moving relative to each other. We know from the laws of physics that warm air rises and cold air sinks. It is when light passes this layer boundary that we observe flicker.

Passing through the layers of air, different in density, the light of the stars begins to flicker, and their outlines blur and the image increases. In this case, the intensity of the radiation and, accordingly, the brightness also change. Thus, by studying and observing the processes described above, scientists have understood why stars twinkle, and their twinkling varies in intensity. In science, this change in light intensity is called scintillation.

Planets vs Stars: What's the Difference?

Another interesting fact is that not every cosmic glowing object outgoing light gives the phenomenon of scintillation. Let's take planets. They also reflect sunlight but do not flicker. It is by the nature of the radiation that a planet is distinguished from a star. Yes, the light of a star gives a twinkling, but the planets do not.

Since ancient times, mankind has learned to navigate in space by the stars. In those days when precise instruments were not invented, the sky helped to find the right path. And today this knowledge has not lost its significance. Astronomy as a science was born in the 16th century when the telescope was first invented. It was then that they began to closely observe the light of stars and study the laws by which they twinkle. Word astronomy in Greek it means "the law of the stars".

Star science

Astronomy studies the Universe and celestial bodies, their movement, location, structure and origin. Thanks to the development of science, astronomers have explained how a twinkling star in the sky differs from a planet, how development occurs celestial bodies, their systems, satellites. This science has looked far beyond the boundaries of the solar system. Pulsars, quasars, nebulae, asteroids, galaxies, black holes, interstellar and interplanetary matter, comets, meteorites and everything related to outer space, studies the science of astronomy.

The intensity and color of the twinkling starlight is also affected by the height of the atmosphere and the proximity to the horizon. It is easy to see that the stars located close to it shine brighter and shimmer different colors. This spectacle becomes especially beautiful on frosty nights or immediately after rain. At these moments, the sky is cloudless, which contributes to a brighter shimmer. Sirius has a special radiance.

Atmosphere and starlight

If you want to observe the stellar twinkling, you should understand that when calm atmosphere at the zenith this is possible only occasionally. Brightness luminous flux constantly changing. This is again due to the deflection of light rays, which are unevenly concentrated over earth's surface. The wind also influences the starry landscape. In this case, the observer of the stellar panorama constantly finds himself alternately in a darkened or illuminated area.

When observing stars located at an altitude of more than 50 °, the change in color will not be noticeable. But the stars that are below 35 ° will twinkle and change color quite often. Very intense flickering indicates the heterogeneity of the atmosphere, which is directly related to meteorology. During the observation of stellar twinkling, it was noticed that it tends to increase with reduced atmospheric pressure, temperature. An increase in flicker can also be seen with increasing humidity. However, it is impossible to predict the weather from scintillation. The state of the atmosphere depends on a large number various factors, which does not allow one to draw conclusions about the weather only from star twinkle. Of course, some points work, but so far this phenomenon has its own ambiguities and mysteries.