What does the circle around the sun mean. What is a halo around the sun or moon? How to look at the solar halo

Physics of the phenomenon

The halo usually appears around the Sun or Moon, sometimes around other powerful lights such as street lights. There are many types of halo, but they are mainly caused by ice crystals in cirrus clouds at an altitude of 5-10 km in the upper troposphere. The form of the observed halo depends on the shape and arrangement of the crystals. The light reflected and refracted by ice crystals is often decomposed into a spectrum, which makes the halo look like a rainbow, but the halo in low light conditions has a low color, which is associated with the features of twilight vision.

Refraction of light on ice crystals

Sometimes in frosty weather, the halo is formed by crystals very close to the earth's surface. In this case, the crystals resemble shining gems.

Observation and photography technique

Since the halo is very bright (we can say that the halo is a reflection of the sun), any camera will shoot it at any settings, but because of this brightness, poorly captured details are obtained: if the sun itself gets into the frame, the halo will look dull, colors will disappear.

solar pole

Light, or solar, pillar represents a vertical band of light stretching from the sun during sunset or sunrise. The phenomenon is caused by hexagonal flat or columnar ice crystals. Flat crystals suspended in the air cause solar pillars if the sun is at a height of 6 ° above the horizon or behind it, columnar - if the sun is at a height of 20 ° above the horizon. Crystals tend to take a horizontal position when falling in the air, and the shape of the light column depends on their relative position.

see also

Notes

Literature

• Zvereva S. V. In the world of sunshine. - L.: Gidrometeoizdat, 1988. - 160 p.

• M. Minnart."Light and Color in Nature" is a rather old book, describing a dozen different types of halo, including 46 degree parhelia, which are now considered impossible.
• Frederick K. Lutgens, Edward J. Tarbuck, Dennis Tasa The Atmosphere: An Introduction to Meteorology. - 11. - Prentice Hall, 2009. - 508 p. - ISBN 0321587332

• Alf Nyberg Himlasken och andra ljusphenomen. - Ingenjörsförlaget, 1985. - 133 p. - ISBN 9172841923

Links

Wikimedia Foundation. 2010 .

See what "Halo" is in other dictionaries:

Halogen... Russian word stress

halo- neskl., cf. halo m. In astronomy, iridescent or white circles, spots, etc. around the Sun, Moon, arising from the refraction or reflection of light by ice crystals in the upper atmosphere. BAS 2. The upper layers of the atmosphere were tightened ... ... Historical Dictionary of Gallicisms of the Russian Language

Rainbow rings around the sun and moon. Dictionary of foreign words included in the Russian language. Chudinov, A.N., 1910. HALO iridescent rings appearing from time to time around the sun and moon. Dictionary of foreign words included in ... ... Dictionary of foreign words of the Russian language

unchanged; cf. [from Greek. halōs circle, disk]. Astron. Iridescent or white circles, spots, etc. around the disks of the Sun and Moon, arising from the refraction and reflection of light by ice crystals suspended in the air. * * * halo (from Greek hálōs … … encyclopedic Dictionary

- (Halos) bright or iridescent circles of large diameter around the sun and moon, separated from the luminary by a dark gap; are often observed in cases where the sun and moon are visible through light cirrus clouds or through a veil of fog, ... ... Marine Dictionary

Halo... (gr. hals (halos) salt) first component compound words, corresponding in meaning to the word salt, for example. halophytes. New dictionary foreign words. by EdwART, 2009. halo... [Dictionary of foreign words of the Russian language

Halo- in Antarctica. HALO, light circles, arcs, pillars, spots, observed from the Earth around or near the disks of the Sun and Moon. Caused by the refraction and reflection of light by ice crystals suspended in the air. … Illustrated Encyclopedic Dictionary

Wed bent, a projectile for bending arcs, rims and skids: a circle was cut in cohesive bars or died a furrow; a chopping block, steamed in a steam engine, or underground, on which a large fire is laid out, is embedded in a halo and wedged. Dictionary… … Dahl's Explanatory Dictionary

halo- A ring of light around the Sun or Moon, resulting from the refraction and reflection of light in ice crystals, the halo includes colored circles, arcs, pillars, spots, etc. → Fig. 144 ... Geography Dictionary

HALO, light circles, arcs, pillars, spots, observed from the Earth around or near the disks of the Sun and Moon. Caused by the refraction and reflection of light by ice crystals suspended in the air... Modern Encyclopedia

- (from the Greek halos circle disk), light circles, arcs, pillars, spots observed around or near the disks of the Sun and Moon. Caused by the refraction and reflection of light by ice crystals suspended in the air... Big Encyclopedic Dictionary

Books

• Instructions for first aid in case of accidents at work, Bubnov Valery Georgievich, Bubnova Natalya Valentinovna. The instruction was developed in accordance with the State General Educational Standard Russian Federation and the Atlas of a Volunteer Rescuer, recommended by the Russian Emergencies Ministry for mass ...

Seeing a rainbow, most of us smile and remember childhood when it a natural phenomenon was seen for the first time. There are many signs associated with, but a multi-colored arc that closes around the sun looks especially unusual and mystical. In science, this phenomenon is called a halo.

What is the phenomenon of a rainbow around the sun?

There are many types of halo, but all are caused by ice crystals in cirrus clouds. It is from their shape and location that the appearance of the halo depends. The light reflected and refracted by ice crystals is often decomposed into a spectrum, which makes the halo look like a rainbow. The halo that forms around the moon has no color, because at dusk it is simply impossible to distinguish it. This phenomenon is fixed in any weather, and in frost, the crystals are located very close to the surface of the earth and resemble shining precious stones, the so-called diamond dust.

The lower part of the halo can be seen against the background of the surrounding landscape if the main luminary is located low above the horizon. However, halos are not the same as crowns. The last natural phenomenon is associated with the formation of light hazy rings in the sky around the Sun or Moon.

What does a rainbow around the sun mean?

Those who are lucky enough to see this rare phenomenon should expect all the very best - well-being, prosperity, good luck and love. If before that there was not the easiest period in life, then it will definitely end and everything will work out in the best way.

If there are such signs associated with a circular rainbow around the sun:

There is a mass historical facts associated with the halo, when this natural phenomenon helped those who saw it in any business or vice versa, was interpreted as a bad sign. In particular, the Tale of Igor's Campaign says that the army was finally defeated when four Suns appeared in the sky. Ivan the Terrible regarded the natural phenomenon he saw as an omen of imminent death. There are a lot of signs about the rainbow. Such a belief is quite interesting: having taken a sip of water from the river from where the rainbow originates, she can guess the gender of her child. True, this applies only to those women who already have three daughters or three sons.

The optical effect of the halo has been observed by the inhabitants of the Earth throughout history. This extraordinarily beautiful phenomenon in the Middle Ages was mistaken for the swords of angels (pillars and arcs) and for angel dust, when the halo formed too close to the surface of the Earth, and its appearance resembled a scattering of precious stones. Today we will talk about the scientific origin of the halo effect and its varieties.

What is a "halo"?

Surely, everyone knows the case when information appeared on the Internet that three suns rose at once on the territory of Chelyabinsk. AT recent times in general, there is a lot of information about the occurrence of the northern lights in areas and areas where there was no such phenomenon before. Also, many people say that on a frosty winter day they observed a rainbow. Is it possible? Of course, many immediately began to discuss the coming end of the world, and the more superstitious started talking about the approach of the Apocalypse! But all this is just fiction, all these unusual phenomena are called the “halo effect”.

The sun or moon can be the cause of this optical miracle, and it only happens in winter. A halo is simply the reflection of the sun's or moon's rays off ice crystals. These crystals are hexagonal in shape and light can pass through them in any direction, straight or oblique. Basically, the halo effect is reproduced at very high altitudes, in cirrostratus clouds. They form a warm cyclone, and therefore the appearance of the halo effect serves as a signal that warm weather is coming.

The difference between the halo effect and the "Solar crown"

The halo effect appears around the Sun or Moon in frosty and humid weather. It is a glow around these bodies, has a bright color. "Solar crowns", in turn, are the glow around the Sun, the Moon, searchlights or street lamps, which occurs under similar conditions, but it is still a hazy glow. These are different phenomena, although their origins are similar in nature, and they should not be confused.

How is a rainbow different from a halo?

The halo effect, the photo of which you see in this article, is, in fact, a rainbow. But still not quite. Rainbows form on warm days and appear from the sun's (and only the sun's) rays reflected in water droplets. That is, in a warm summer rain or immediately after it, we can observe a rainbow. This phenomenon consists of the entire spectrum of colors, and it can only be seen by turning away from the sun in the opposite direction, that is, with your back to the luminary. The rainbow always appears in the same place, and the red color is located on the outer (farthest from the horizon) line. The rainbow is always the same, since water droplets differ only in size, but in the atmosphere they behave exactly the same.

Quite another thing is the halo effect! Ice crystals are not only different in size and shape - they, unlike drops, can move freely independently of each other: hover, fall down or rotate. Due to this, various phenomena arise - circles, arcs, pillars, a false Sun.

A halo, unlike a rainbow, occurs around the luminary, and not in the opposite direction from it, and can appear at night. It has only two colors - red and orange, and the first is closer to the horizon, that is, from the inside. The rest of the colors blend together and resemble a white glow. Of course, there are brighter and more spectacular halos, consisting of all colors, but this phenomenon is extremely rare and is an amazing sight!

Solar halo: varieties

We examined the origin of the halo effect, understood what it is, how it differs from two other optical phenomena. It remains only to understand its varieties.

The halo effect comes not only in different colors, but also in sizes and shapes. The most common phenomenon is located very close to the Sun or the Moon, this is the so-called 22 0 halo. For the most part, it consists of two colors, red and orange, less often they are complemented by a white glow.

A rarer phenomenon is the 460 halo. It is located further from the Sun and can be painted with all colors. The rarest halo effect occupies the entire sky. This phenomenon is rarely seen.

There is also a subhalo. Its origin is exactly the same as that of the halo, only it is located in the horizontal plane, and not in the vertical one.

Halo effect after laser vision correction

Medicine does not stand still, and many people can forget about wearing glasses or contact lenses once and for all without surgery. Laser vision correction has become a very popular and practically safe operation if done by an experienced surgeon.

Some patients, after undergoing this correction, complain about the appearance of photosensitivity or even unpleasant light glare before their eyes, most often in the dark. This side effect called a halo, or star formation. It can greatly complicate life - with such vision it is impossible to drive a car at night and at dusk, since all luminous objects (lanterns, lights of oncoming cars, etc.) become like light balls from which rays emanate, often the road itself forks . At the same time, vision itself can be sharp, completely normal. If such an effect appeared, then there is a possibility that a mistake was made in the correction or it was carried out with old equipment. You should contact the clinic where you had the operation to get rid of the halo.

How to properly observe a halo?

People who have noticed an unusual glow in the sky, of course, strive to examine it properly, but the halo effect is not so safe for the eyes. When observing this phenomenon, it is necessary to protect your eyesight in order to protect against UV radiation. In order not to damage the retina of the eye when viewing the halo, you need to arm yourself with sunglasses or cover the luminary with some object, you can also use your hand. The same method should be used when photographing the phenomenon, as the photos may turn out to be of poor quality, blurry.

Seeing the halo is amazing! And if you managed to see a rare multi-colored phenomenon, then it will remain in your memory for a long time.

How did the halo effect affect the course of history?

We have already said that the halo was previously perceived as something supernatural, and most often it was taken as not the best sign. So, this natural optical effect could significantly affect the whole story.

In 1551, Charles V, seeing a halo effect in the sky, refused to besiege Magdeburg. He considered this phenomenon to be a heavenly protection that protected the besieged and brought punishment to Charles in the event of a continuation of the siege.

The Tale of Igor's Campaign tells that the prince took the solar eclipse as a sign that would cover his troops with darkness, and went into battle. The Polovtsians began to overcome Igor's army, and then four Suns rose. Again, Igor took this as a good sign for him and did not back down. As a result, all the Russians perished, and Igor himself was captured.

There are many such examples, and it makes no sense to describe them all. It remains only to say that the halo effect does not carry any threat or omen, it is just a beautiful natural phenomenon.

We all remember the lines of Pushkin's poem “Frost and Sun; wonderful day!" And what is so wonderful you can see in the sky in a frosty sunny winter morning? The “morning miracles” undoubtedly include the phenomenon of the halo. The photos show what it might look like. Today we will talk about what it is, how such things appear in the sky, when and how it is best to observe.

What is a halo?

halo is optical phenomenon created by tiny ice crystals of ice in the atmosphere. Most often, it looks like light circles, arcs, spots, and even pillars of light around or near the disks of the Sun and Moon. Halo can also be seen around street lamps, but for the appearance of any impressive picture in the sky, a more powerful light source is needed. Therefore, all the most beautiful halos are observed in daylight or at dusk.

How is a halo formed?

For the fact that we sometimes observe a halo, we must thank physical phenomenon called the refraction of light. Everyone has noticed a thousand times that a teaspoon dipped into a glass of water looks bent or even broken at the water-air interface. This happens because light slightly changes its direction when moving from one medium to another. The same thing happens with light when crossing the boundary of other media, for example, ice crystals. Depending on the orientation of the crystals and the position of the Sun or Moon in the sky, different types of halo can be observed. The simplest halo that is most commonly observed is the twenty-two degree halo (halo 22⁰). Crystals of frozen water floating in the air different shapes and sizes, but most often regular hexagonal rods of different lengths are formed. All of them are oriented in the air in a completely random way.

There are millions of such crystals-rods, so there will always be those whose axes are approximately perpendicular to the rays coming from the Sun (as in the picture).

It turns out that due to the geometric properties of regular hexagons, light passing through one of their faces will deviate by a small angle ranging from 22 to 27 degrees, which will create a luminous circle around the Sun or Moon.

There are more than one hundred and fifty types of halo, and all of them are classified either by their position in the sky relative to the Sun, or by the name of the person who first described this type of halo. The phenomenon of parhelion stands apart here. Parhelion is Latin for "false sun".

Photo taken in Stockholm

Parhelion is just one type of halo, but by far the most impressive. Ice crystals are also responsible for such beauty in frosty weather, only this time not in the form of rods, but in the form of plates. All ice crystals gradually settle to the surface of the Earth, but they are so light that the process of falling can take several hours.

During such a gradual fall, it would be more accurate to say, "settlement" down, most of the crystal plates line up horizontally. This rather strange behavior for plates is explained by the Bernoulli phenomenon. When the plate falls down, air flows around it from all sides. At the edges of the plate, the air flow velocity is greater than in the center, and because of this, the pressure from the edges drops slightly.

It turns out that the air, as it were, drags the plate in a horizontal direction in all directions and does not allow it to tilt. The refraction of light in such plates creates the apparent satellites of the Sun in the sky.

If you are lucky, then the same phenomenon can be seen at night. A false moon, or paraselena, is also two bright spots that appeared to the left and right of the light source - the moon. Paraselena is formed in the same way as parhelion. However, a false moon is a much rarer phenomenon than parhelion: for its appearance, it is necessary full moon. So watch the moon more often on frosty evenings. If you see paraselena - know that such cases are one in a million.

To give you the right impression of how many halos you can see in the sky at one time, take a look at this photo.

It was taken by American photographer David Hathaway at the end of October 2012. In one photo, as many as ten different halos fit here. Vladimir Galynsky simulated observational conditions that could give a similar picture.

Can you see a halo at the equator?

Oddly enough, halos can be seen even in very hot countries. Maybe it will not be as beautiful and impressive as in the middle latitudes or at the north pole, but you can definitely see the 22 degree halo. The fact is that the halo is formed mainly due to the scattering of light by ice crystals, which are high, high in the air, where the air temperature is negative.

This photo was taken at 7 am in Indonesia, just one degree of latitude from the equator.

How to observe a halo?

Look more at the sky. Oddly enough, this is the most useful advice everyone. Even if the sky seems completely clear to you, there may still be a thin layer of clouds that is imperceptible at first glance, forming a halo.

Look for the most common halo first- 22 degrees. By the way, if you stretch out your hand and block the center of the sun with the end of your thumb, then the protruding little finger should be approximately at a distance of a twenty-two degree halo. Check if there is a tangent to the big halo (see Galynsky's simulation)? Check for a small inconspicuous parhelion? If the sun is low on the horizon, look for a skylight.

Look for rare halos. Will you ever get lucky? The most "common" rare halo is 46 degrees. Halo. Look for it at twice the distance from the sun as 22 degrees. It is believed that in Russia it can be seen 4-8 times a year. Wrap around yourself, if there are fragments of a parhelic circle somewhere (it crosses the whole sky). Take a closer look at the area above the sun - what if there is an arc of Parry lurking there, which you did not notice from the very beginning?

Look for derivatives of visible halos. If you see bright parhelion, it means there are a lot of flat hexagonal ice crystals in the air. Such crystals form and 120 deg. Parhelion.

Look for something out of the ordinary. Seeing different halos in the sky in large numbers, scan the entire sky with your eyes, it is quite possible that you will notice something very rare. Sometimes rare halos appear on their own, without any warning.

Record everything what you saw in a notebook or phone. Especially pay attention to the time to the nearest minute, this will help you later determine the exact height of the sun above the horizon. Take pictures. If you don’t have a camera at hand, then at least just sketch what you see, this can also bring a lot of benefits! Suddenly you saw a halo that was only theoretically predicted, but no one has ever seen it?

Walk a hundred or two hundred meters to the side and look at the sky again. Halo is a unique phenomenon for each point of observation. Two people of different height standing side by side can see different types halo. This is due to the fact that ice crystals must be strictly oriented along the line between the observer and the sun. If you step aside, the orientation of the ice crystals in the air relative to you will change, and you will see something new.

Good luck with your observations!

And on other planets?

As you understand, on other planets solar system no one has been yet. Therefore, it may well be that in 20 years you will be the first (I wonder if girls read these stories?) to see, and then tell all of humanity what halos look like on other planets. But even now we can figure something out. To do this, you need to know what type of matter can form crystals in the atmosphere of other planets.

Mars

A halo formed by clouds of frozen CO2 and water vapor. The already familiar 22⁰ halo (inner) is girdled by the 26⁰ halo and the 36⁰ halo, which create carbon dioxide crystals. Unusual parhelia appear.

Jupiter

A halo formed by octahedral ammonia crystals. An octahedron is two pyramids folded together at the bases (forgive me mathematicians). In such crystals, due to their geometric features, light will be refracted differently than in crystals of water familiar to us. The halo will be at 42⁰, and will be accompanied by twice the parhelion.

Konstantin Kudinov

Dear friends! If you liked this story and want to keep abreast of new publications about astronautics and astronomy for children, then subscribe to the news of our communities

The sky is an amazing thing, constantly changing and diverse. But how often do we turn our attention to the sky? Usually people do not notice and are not interested in what is happening in the sky. And only when strange phenomena occur in it, attention to it rises and they begin to say that the sky gives people signs. One of these unusual natural phenomena is considered halo arcs of light or circles around the sun or moon. But where do they come from and why do they disappear as suddenly as they appear? Let's look into this issue together.

So the word " halo" comes from the Greek word " galos', which means 'circle' or 'disk'. The natural phenomenon closest to the halo, which is well known to us, is the rainbow, that is, the refraction of the rays of the heavenly body. But unlike a rainbow, which can be observed only in the daytime, standing with your back to the sun, in moisture-saturated air, a halo appears in the sky at any time of the day - around the sun or moon (and sometimes near a powerful source of artificial light).

Nature halo phenomena in the sky (5-10 km above the earth, in the upper layers of the troposphere) - refraction and decomposition into a spectrum of light rays ( dispersion) in the smallest ice crystals, as well as their reflection from the side faces or bases of these crystals, which have the shape of hexagonal columns or plates. Crystals can be of different sizes and have different nature of its origin in the atmosphere, but at the same time obey the uniform laws of physics - gradually fall, rotating at the same angular velocity for everyone, hover motionlessly or oscillate harmoniously.

Arcs or circles forming a halo appear at some distance from the luminary, equidistant from the light source. Sometimes, in addition to the circle or its segments (arcs), a second one also appears, located further than the first, but always at the same distance from the luminary. On these arcs and circles there may be bright spots of light - false suns or false moons. There are several of them, but they all always stand at the same height above the horizon as the luminary itself, and sometimes even opposite it, on the other side of the sky.

Refraction of light in the sky

If you rely on halo phenomenon observation statistics in the sky, we can conclude that the appearance of a halo is typical for cirrostratus clouds, in which sunlight is refracted in a complex way, reflected and scattered in small crystals - hexagonal ice prisms, pyramids, columns or plates. Due to the optical properties of these crystals, which have a more regular structure than water droplets, the halo looks much more picturesque than halos and crowns. Often cirrostratus clouds portend the approach atmospheric front, so the appearance of a halo can predict worsening weather.

When the rays of the sun pass through cirrostratus clouds, which consist of glacial crystals, light oblique crosses, arcs, additional (false) suns, luminous pillars from the horizon line to the luminary and other pictures resembling certain objects may appear in the sky. Such phenomena in the Russian chronicles were called "halos", and now they are called solar halo.

Earlier in people the appearance of a halo in the sky caused fear and panic - they seemed like bloody swords and were interpreted as harbingers of great trouble - the beginning of war, famine, epidemics, etc.

On the other hand, a change in the weather, on the eve of which halos often appear in the sky, is also an unpleasant thing, especially when we are talking about natural disasters.

Forms and types of halo

The shape of the halo depends on the position of the crystals relative to each other when they fall in the atmosphere, when they experience atmospheric braking and take a position in which the greatest air resistance is created. however, Brownian motion and atmospheric fluctuations prevent this, as a result of which small crystals are arranged randomly in the cloud, and large columnar crystals and plates are more subject to atmospheric drag due to their surface area, so they fall oriented.

halo shapes

• The halo can be seen most often in the form a circle painted with all the colors of the rainbow around the sun with an angular radius of 22°.
• Slightly less common halo in the form of concentric circles with it the second circle with an angular radius of 22° and 46°.
• And very rare halo Hevelius– 90° circle.
• Sometimes you can watch white horizontal circle(parhelic circle), parallel to the plane of the horizon and passing through the sun. At the intersection of this circle with the 22° and 46° halo circles, bright iridescent spots appear - false suns ( parhelia), as well as false moons ( parcelins).
• It also happens that only visible the lower halves of the halo, as well as elliptical halo. Among these unusual forms are rainbows curved into reverse side . Most likely, these are the lower parts of the 46° or 90° halo circles.

halo types

Where and when can you see the halo

Most often halo can be seen in Antarctica on its ice dome and on slopes located at an altitude of 2700-3500 m above sea level. There they can be observed throughout the day, while their shape and color can change. Permanent strong winds lift into the air clouds of loose snow, having a crystalline structure. The lower boundary of such snow clouds descends to the ground itself, creating ideal conditions for the formation of a halo. In the absence of snow clouds and in bright sunshine numerous colored and white halos with a radius of 22° and 46° occur, as well as other rarer phenomena.

Moisture-saturated air tends to crystallize when cooled. When carrying large volumes of wet air masses in the upper layers of the atmosphere over the continent, moisture condenses, crystallizes and frost falls. AT warm time years, ice crystals do not reach the surface of the earth and dissolve in the lower layers of the atmosphere, again saturating the air with moisture. Therefore, the halo phenomenon is more likely to be observed on the continental part of the continents than near the coast.

Sometimes in frosty weather, a halo forms near the earth's surface, and ice crystals in the air sparkle like gems, enhancing the radiance of the halo. If the sun is low on the horizon, then the lower part of the halo can sometimes be observed against the background of the surrounding landscape.

Our observations of a halo in the sky

We have seen this phenomenon many times, but not every time we had a camera with us. But we especially remember two cases: when we were driving along the Dmitrov highway towards Moscow, and a spectacular solar phenomenon accompanied us almost the entire trip. And on another sunny day in Pai in Northern Thailand, we saw a very beautiful circle of light in a clear sky.

Halo in the photo

Halo in Thailand, Pai city