Mar 19 2012
If you ask someone: “how many stars are there in the sky?”, then you hear the standard answer - a lot, more than the hair on your head, drops in the ocean, etc. So how many?
A person with good eyesight sees stars of the so-called 6th magnitude - designated 6m. And he can see about 6000 of them, but this is in 2 hemispheres. In one there are 3000, but near the horizon the transparency of the atmosphere decreases, and about 2000 stars are visible. Just.
But if you pick up binoculars, you can already see stars of magnitude 9m - 10m, and there are about 200 thousand of them in the sky. What a difference it makes!! And in a small telescope up to 11-12m. There are 2 million stars with such brilliance. In powerful telescopes, stars up to 15-16m can be distinguished. There are more than 100 million of them.
But this is how many stars we can see, but how many of them are there in reality? There are no exact answers, but:
- There are an estimated 200 billion stars in our Milky Way galaxy!
- In the neighboring Andromeda galaxy - 1 trillion - 5 times more!
- There are 100 trillion stars in the large elliptical Abell galaxy!
- The number of galaxies available to us for viewing is hundreds of billions!
So consider it. The number of stars according to current calculations is 10^24, that’s 1 followed by 24 zeros!!!
Hubble Far Field
The image shows the far field of the Hubble telescope - The stars are no longer visible individually here - that's all!!!
1,000,000,000,000,000,000,000,000 stars. And our Sun is also a star, and a small one, but its diameter is only 1.39 million kilometers.
Two thousand years ago, in order to somehow classify the whole variety of stars in the sky, scientists introduced a division of stars by brightness into six groups, into six. These are the stars that are visible to the naked eye.
The brightest stars (about twenty of them in total) were called stars, the fainter ones - stars of the second magnitude, and those that are barely visible - stars of the sixth magnitude.
The brighter the star, the smaller its magnitude. There is nothing surprising about this division of stars according to their brightness. It doesn’t surprise anyone that the largest fruits are classified as the first grade, smaller ones - as the second grade, etc.
Compared to stars of the first magnitude, stars of the sixth magnitude shine a hundred times weaker. Stars of the seventh and eighth magnitudes visible through binoculars are two and a half and six times fainter, respectively.
Take a closer look at the starry sky, find constellations on it using a star map, and you will soon see how easy it is to navigate the sky and keep track of all the stars visible to the naked eye.
There are about six thousand such stars in total, and no more than three thousand of them are visible immediately above the horizon. If we say “about”, it is only because visual acuity and air transparency vary.
With average binoculars, the number of visible stars increases to approximately 10,000, and on photographic plates obtained at long exposures using the most powerful telescopes in operation, the number of stars in the entire hemisphere is 2-3 billion. Most of them belong to and only the brightest stars can be distinguished in photographs.
If we mentally divide the celestial sphere into squares, each of which is equal in area to the disk of the full Moon, as seen from the Earth (the result is 200,000 squares), then in each of these squares, if we had a super-powerful telescope, 10,000 stars would be visible.
Of course, all this diversity is almost invisible to us - stars above the 6th magnitude cannot be seen without a telescope, but as the brightness of stars decreases, their number increases. This means that the night sky hides much more from us than it shows!
The lists of star catalogs include not only all stars visible to the naked eye, but also many fainter ones.
All stars brighter than the eleventh magnitude have been counted and cataloged, as well as on maps. We also know the number of fainter stars, but not so accurately, and this is not so important.
As a result, the count of the number of stars brighter than a given limiting magnitude can be represented by the following table ( the data is outdated, now an order of magnitude more stars of all magnitudes given in the table are known. However, the proportions of magnitude/number of stars remained the same and clearly demonstrate the general trend):
| Ultimate starmagnitude | Number of stars |
| 6,0 | 4 860 |
| 7.0 | 14 300 |
| 8,0 | 41 000 |
| 9,0 | 117 000 |
| 10,0 | 324 000 |
| 11,0 | 870 000 |
| 13,0 | 5 700000 |
| 15,0 | 32 000 000 |
| 17,0 | 160 000 000 |
| 19,0 | 560 000 000 |
| 21,0 | 2 000 000 000 |
By the way, the magnitude can be not only positive, but also negative! In fact, the most bright Star- nothing compared to the light of the same Moon, but the Moon is also a cosmic object! In other words, in our time, “stellar magnitude” has become not so much a “stellar” magnitude as a “general cosmic” magnitude.
For comparison, I will give comparison table stellar magnitudes containing information about all significant space objects that can be observed from Earth.
| name of the property | Magnitude (m) |
|---|---|
| Sun (from Earth) | −26,7 |
| Sun (from Pluto) | −18,2 |
| Moon (full) | −12,74 |
| 1054 Flash | −6,0 |
| Venus (maximum brightness) | −4,67 |
| Jupiter (maximum brightness) | −2,94 |
| Mars (maximum brightness) | −2,91 |
| Mercury (maximum brightness) | −2,45 |
| Saturn (maximum brightness) | −0,24 |
| Stars of Ursa Major | +2 |
| Andromeda Galaxy | +3,44 |
| Moons of Jupiter | +5-6 |
| Uranus | +5,5 |
| Faintest stars observed naked eye |
From +6 to +7.72 |
| Neptune | +7,8 |
| Proxima Centauri | +11,1 |
| The brightest quasar | +12,6 |
| Faintest object captured by a ground-based telescope (8 m) | +27 |
| Faintest object captured to the Hubble Space Telescope |
+31,5 |
Since ancient times, people have looked at the night sky and been amazed at how densely it is dotted with stars. The number of shining points in the sky has worried humanity for thousands of years.
Ever since Ancient Greece scientists tried to count the stars, but even now, in the century high technology and ultra-precise instruments, modern astronomers can only approximately answer the question of how many there actually are.
The first catalog of stars in our history was compiled by the astronomer Hipparchus. Using a primitive telescope, he was able to detect about 1000 celestial bodies in the sky and determine their exact coordinates. It was he who came up with the concept of “stellar magnitudes,” which astronomers use to this day.
The essence of this system is that all objects in the Universe are located at different observable magnitudes - the brighter the star, the smaller its magnitude. Initially, he divided all the stars into 6 magnitudes. The last, sixth, included the least bright ones, which can barely be seen with human vision. Subsequently, scientists discovered many other quantities that were visible only with the help of special instruments.
How many stars are there in six magnitudes? In other words, how many stars can we see at night with the naked eye? It is believed that people with perfect vision see no more than 5-6 thousand simultaneously in both hemispheres.
In one hemisphere, only 2–3 thousand celestial bodies are visible, however, due to artificial lighting at night and a decrease in atmospheric transparency near the horizon in major cities this amount decreases tenfold. With binoculars you can see up to 200 thousand stars, amateur telescope- about 10 times more.
solar system is one of the planetary systems of our galaxy and includes only one star - . All other objects in it are planets, satellites, asteroids, comets and other cosmic bodies. The sun appeared about 4.57 billion years ago and is currently in its prime. 
Its mass is so great that it easily holds near itself and makes all smaller objects move. Unlike other stars, you can see the Sun not at night, but during the day, since at night it disappears below the horizon.
The galaxy in which our planet is located. In addition to the Sun, it supposedly includes 200 billion stars, although some scientists suggest that their number reaches 400 billion. In photographs of the sky taken by the most powerful telescopes, you can see so many stars that astronomers consider it pointless to count them and give names.
Only 0.01% of all the stars in the Milky Way are numbered and cataloged, and even fewer have names - only about 300 stars. As a rule, names are assigned only to the largest and brightest objects, such as Sirius, Polaris, Antares, Proxima Centauri.
Astronomers drew many star names (Aldebaran, Rigel, Algol) from folk tales, parables or legends. Some stars were named in honor of the astronomers who first described them - Bernard's star, Kapteyn's star.
Nobody knows the number of stars in the Universe. It is infinite and in its observable part (visible through the Hubble telescope) contains about a trillion galaxies. IN Milky Way There are approximately 200 billion stars, but there are galaxies that are 20 times larger than ours.
Each of them contains many hundreds of billions of stars, so it is not possible to count them. According to scientists, on average, about 10 24 (10 to the 24th power) stellar objects are available for observation, although it is possible that this number is much higher.
Do you know how many stars are in the sky? People have always been interested in this question, and scientists have always argued about it. So I decided to write a blog article on this topic.
If you are interested in this or if your child is asking this question, read this to him. short story about what children think about stars and what scientists say.
One evening Pavlik, Taras and Anya looked at the sky. It was dark and everything was strewn bright stars. And it seemed that with every minute there were more and more stars.
How many are there in the sky? - asked Anya.
I think several hundred,” said Taras.
- No, that’s not enough, look how big the sky is.
There are apparently several thousand stars! - said Pavlik.
- Let's count! — the children cried out together and began to count in unison.
- One, two, three, four... - they counted as many as they knew the numbers and they were tired. - Are there really so many of them that it’s impossible to count them all?
“Even astronomers can’t count all the stars.” And they have been studying photographs of the night sky for many years. It’s difficult to count the stars, not only because there are so many of them, but also because some of them disappear from the sky over time, while others, on the contrary, appear,” Anya intervened in the conversation. “And now a star has fallen from the sky, quickly make a wish!”
It seems that the stars in the sky are scattered randomly. But that's not true. Even in ancient times, people, peering into the sky, noticed that the stars seemed to be creating patterns on a dark canvas. These drawings are called constellations. Constellations divide the sky into certain areas.
To the ancient Greeks, the constellations resembled images of famous heroes - Hercules, Perseus, the outlines of animals and objects - the Dragon, Swan, Lyra.
Some constellations can be easily seen even without a telescope. For example, the constellation Ursa Major: these are seven bright stars that are located in the sky in the form of a bucket. And next to these seven bright stars there are other, less bright stars - they resemble the head and legs of a beast. But, nevertheless, this is not really a bear, because the bear in reality has a short tail, and not the same as in the celestial drawing.
There is also the constellation Ursa Minor next to the Big Dipper. In the “tail” of Ursa Minor is the North Star, the brightest star in this constellation. As the Earth moves, the stars rise in the East, and in the West they sink lower and lower until they set completely. Only the North Star remains motionless. It always remains above the North Pole. To find this star, you need to find the constellation Ursa Major (Big Dipper) and extend the line that connects the two outermost stars of this bucket.
How many stars are there in the sky according to scientists?
Once upon a time there lived a Greek scientist named Hipparchus, who tried to count all the stars in the sky and catalog them. The scientist divided all the stars into six different groups (magnitudes), depending on how bright they were. The dimmest stars were the sixth magnitude.
In general, in the galaxy, different scientists count from 200 billion to a trillion different stars!
How many stars can a person see? At the same time, with a simple glance, a person can see from 1.5 to 2.5 thousand stars. It depends on how clear the sky is, and also on how much lighting there is around the person. The darker it is around, the more stars will be visible.
If a person looks at the sky through binoculars, he will be able to see up to 200 thousand stars, and with a simple telescope this figure is 10 times more. If the telescope is very powerful, then more than 100 million stars can be distinguished!
All these figures are, of course, approximate, but humanity will most likely never know the exact answer to the question of how many stars are in the sky, especially since a huge number of them are hidden behind galactic dust.
And, finally, I suggest watching a very beautiful video with pleasant music about the stars and about our earth in general. This video has received a huge number of views, have you seen it?
It is believed that up to 6,000 stars can be observed with the naked eye from the surface of the Earth. But in reality, this number will be much smaller - firstly, in any hemisphere you can see no more than half of this amount, and secondly, we are talking about ideal observation conditions, which in reality are almost impossible to achieve. And when it comes to the farthest visible stars, in most cases, in order to notice them, we need exactly ideal conditions. So, under average conditions, there will be about 1000 stars in the night sky, which generally makes the task of manually counting them feasible.
How far are they? It turns out not too much. With our eyes we see only the brightest stars, which correlates with their distance. Of course, larger and brighter stars are visible in the sky from a greater distance than nearby but dim stars, but this correction is not large. Pay attention to the red circle (more likely even a punch) on the map. Almost all visible stars are located within its boundaries, since the diameter of the galaxy is 100,000 light years, and all stars visible to the eye are no further than 2-3 thousand light years. from U.S.
VV Cephei A is one of the most big stars of our galaxy. According to various estimates, its radius exceeds the solar one from 1000 to 1900 times. It is located 5000 light years away.
Mu Cephei, also known as Herschel's Garnet Star, is a red supergiant, possibly the largest star visible to the naked eye. Its luminosity exceeds the solar one from 60,000 to 100,000 times; the radius, according to recent estimates, can be 1500 times greater than the solar one. Mu Cephei is located at a distance of 5500-6000 light years from us.
Plaskett's Star is located 6,600 light-years from Earth in the constellation Monoceros and is one of the most massive double star systems in the Milky Way. Star A has a mass of 50 solar masses and a luminosity 220,000 times greater than that of our star. Star B has approximately the same mass, but its luminosity is lower - 120,000 solar.
The Eta Carinae system is located at a distance of 7500 - 8000 light years from us. It consists of two stars, the main one - a bright blue variable, is one of the largest and most unstable stars in our galaxy with a mass of about 150 solar, 30 of which the star has already lost. The star's current luminosity is estimated to be at least a million solar and it appears to be a prime candidate for being the next supernova in the Milky Way.
Rho Cassiopeiae is one of the most distant stars visible to the naked eye. It is an extremely rare yellow hypergiant, with a luminosity half a million times that of the Sun and a radius 400 times greater than that of our star. According to recent estimates, it is located at a distance of 8,200 light years from the Sun.
V762 Cassiopeiae is probably the farthest star visible from Earth with the naked eye - at least based on currently available data. This is a red supergiant. According to the latest data, it is located at a distance of 16,800 light years from us.
But even all these stars are not much further than the red region.
There have been cases in history when people were able to observe much more distant stars. For example, in 1987, a supernova that could be seen with the naked eye erupted in the Large Magellanic Cloud, located 160,000 light-years away. Another thing is that, unlike all the supergiants listed above, it could be observed over a much shorter period of time.