The brightest star in the sky. The brightest stars visible from the earth are Sirius, Venus

Want to know which stars are the brightest in the night sky? Then read our rating of the TOP 10 brightest celestial bodies that are very easy to see at night with the naked eye. But first, a little history.

Historical view of magnitude

Approximately 120 years before Christ, the Greek astronomer Hipparchus created the very first catalog of stars known today. Despite the fact that this work did not survive to this day, it is assumed that Hipparchus' list included about 850 stars (Subsequently, in the second century AD, Hipparchus' catalog was expanded to 1022 stars thanks to the efforts of another Greek astronomer, Ptolemy. Hipparchus contributed to his list of stars that could be distinguished in every constellation known at that time, he carefully described the location of each celestial body, and also sorted them on a scale of brightness - from 1 to 6, where 1 meant the maximum possible brightness (or "magnitude") .

This method of measuring brightness is still used today. It is worth noting that in the time of Hipparchus there were no telescopes yet, therefore, looking at the sky with the naked eye, the ancient astronomer could distinguish only the stars of the 6th magnitude (the least luminous) by their dimness. Today, with modern ground-based telescopes, we are able to distinguish very dim stars, the magnitude of which reaches 22m. Whereas the Hubble Space Telescope is able to distinguish objects of magnitude up to 31m.

Apparent stellar magnitude - what is it?

With the advent of higher-precision light-measuring instruments, astronomers have decided to use decimal fractions for stellar magnitudes—2.75m, for example—rather than just crudely labeling magnitudes as 2s or 3s.
Today we know stars whose magnitude is brighter than 1m. For example, Vega, which is the brightest star in the constellation Lyra, has an apparent magnitude of 0. Any star that shines brighter than Vega will have a negative magnitude. For example, Sirius, the brightest star in our night sky, has an apparent magnitude of -1.46m.

Usually when astronomers talk about magnitudes they mean "apparent magnitude". As a rule, in such cases, a small Latin letter m is added to the numerical value - for example, 3.24m. This is a measure of the brightness of a star that a person observes from Earth, without taking into account the presence of the atmosphere, which affects the view.

Absolute stellar magnitude - what is it?

However, the brightness of a star depends not only on the power of its glow, but also on the degree of its remoteness from the Earth. For example, if you light a candle at night, it will shine brightly and illuminate everything around you, but if you move 5-10 meters away from it, its glow will no longer be enough, its brightness will decrease. In other words, you noticed a difference in brightness, although the flame of the candle remained the same all the time.

Based on this fact, astronomers have found a new way to measure the brightness of a star, which has been called "absolute magnitude". This method determines how bright a star would be if it were exactly 10 parsecs (approximately 33 light years) from Earth. For example, the Sun has an apparent magnitude of -26.7M (because it is very, very close), while its absolute magnitude is only +4.8M.

Absolute magnitude is usually given with a capital M, such as 2.75M. This method measures the actual power of the star's glow, without correction for distance or other factors (such as clouds of gas, dust absorption or scattering of the star's light).

1. Sirius ("Dog Star") / Sirius

All the stars in the night sky shine, but none shine as brightly as Sirius. The name of the star comes from the Greek word "Seirius", which means "burning" or "scorching". With an absolute magnitude of -1.42M, Sirius is the brightest star in our sky after the Sun. This bright star is in the constellation Big Dog(Canis Major), which is why it is often called the Dog Star. IN ancient greece it was believed that with the appearance of Sirius in the first minutes of dawn, the hottest part of the summer began - the season of "dog days".

However, today Sirius is no longer a signal for the beginning of the hottest part of summer, but all because the Earth, over a cycle of 25,800 years long, slowly oscillates around its axis. What causes the position of the stars in the night sky to change.

Sirius is 23 times brighter than our Sun, but at the same time its diameter and mass exceeds our celestial body only twice. Note that the distance to the Dog Star is relatively small by space standards, 8.5 light years, and it is this fact that determines, to a greater extent, the brightness of this star - it is the 5th closest star to our Sun.

Hubble image: Sirius A (brighter and more massive star) and Sirius B (bottom left, dimmer and smaller companion)

In 1844, the German astronomer Friedrich Besse noticed the wobble in Sirius and suggested that the wobble might be caused by the presence of a companion star. After almost 20 years, in 1862, Bessel's assumptions were 100% confirmed: astronomer Alvan Clark, while testing his new 18.5-inch refractor (the largest in the world at that time), discovered that Sirius is not one star, but two.

This discovery gave rise to a new class of stars: "white dwarfs". Such stars have a very dense core, since all the hydrogen in them has already been used up. Astronomers have calculated that Sirius' companion - named Sirius B - has the mass of our Sun packed into the dimensions of our Earth.

Sixteen milliliters of Sirius B substance (B is a Latin letter) would weigh about 2 tons on Earth. Since the discovery of Sirius B, its more massive companion has been called Sirius A.

How to find Sirius: The most successful time for observing Sirius is winter (for observers of the northern hemisphere), since the Dog Star appears quite early in the evening sky. To find Sirius, use the constellation Orion as a guide, or rather its three stars from the belt. Draw a line from the leftmost star of Orion's belt, tilted 20 degrees towards the southeast. As an assistant, you can use your own fist, which at arm's length covers about 10 degrees of the sky, so you will need about two widths of your fist.

2. Canopus / Canopus

Canopus is the brightest star in the constellation Carina, and the second brightest star after Sirius in the Earth's night sky. The Carina constellation is relatively young (by astronomical standards), and one of the three constellations that were once part of the huge constellation Argo Navis, named after Jason's Odyssey and the Argonauts who fearlessly set off in search of the Golden Fleece. The other two constellations form the sail (the constellation Sail/Vela) and the stern (the constellation Puppis).

Nowadays, spacecraft use the light from Canopus as a guide in outer space - a vivid example of this is the Soviet interplanetary stations and Voyager 2.

Canopus is fraught with truly incredible power. He is not as close to us as Sirius, but very bright. In the ranking of the 10 brightest stars in our night sky, this star takes 2nd place, surpassing our sun in light by 14,800 times! At the same time, Canopus is located 316 light-years from the Sun, which is 37 times farther than the brightest star in our night sky, Sirius.

Canopus is a yellow-white F class supergiant star with temperatures ranging from 5500 to 7800 degrees Celsius. It has already exhausted all of its hydrogen reserves, and is now converting its helium core into carbon. This helped the star "grow": Canopus exceeds the size of the Sun by 65 times. If we were to replace the Sun with Canopus, this yellow-white giant would gobble up everything before Mercury's orbit, including the planet itself.

Ultimately, Canopus will become one of the largest white dwarfs in the galaxy, and it may even be large enough to completely recycle all of its carbon reserves, making it a very rare type of neon-oxygen white dwarf. Rare because white dwarfs with a carbon-oxygen core are the most common, but Canopus is so massive that it can begin to convert its carbon into neon and oxygen during its transformation into a smaller, cooler, denser object.

How to find Canopus: With an apparent magnitude of -0.72m, Canopus is fairly easy to find in the starry sky, but in the northern hemisphere, this celestial body can only be seen south of 37 degrees north latitude. Focus on Sirius (read how to find it above), Canopis is located about 40 degrees north of the brightest star in our night sky.

3. Alpha Centauri / Alpha Centauri

The star Alpha Centauri (also known as Rigel Centauri) is actually made up of three stars bound together by the force of gravity. The two main (read more massive) stars are Alpha Centauri A and Alpha Centauri B, while the system's smallest star, a red dwarf, is called Alpha Centauri C.

The Alpha Centauri system is interesting to us primarily for its proximity: being at a distance of 4.3 light years from our Sun, these are the closest stars known to us today.

Alpha Centauri A and B are quite similar to our Sun, while Centaurus A can even be called a twin star (both luminaries are yellow G-class stars). In terms of luminosity, Centauri A is 1.5 times the luminosity of the Sun, while its apparent magnitude is 0.01m. As for Centaurus B, it is half as bright as its brighter companion, Centaurus A, in luminosity, and its apparent magnitude is 1.3m. The luminosity of the red dwarf, Centaurus C, is negligible compared to the other two stars, and its apparent magnitude is 11m.

Of these three stars, the smallest is also the closest - 4.22 light years separate Alpha Centauri C from our Sun - which is why this red dwarf is also called Proxima Centauri (from the Latin word proximus - close).

On clear summer nights, the Alpha Centauri system shines in the sky with a magnitude of -0.27m. True, this unusual three-star system is best observed in the southern hemisphere of the Earth, starting from 28 degrees north latitude and further south.

Even with a small telescope, you can see the two most bright stars Alpha Centauri system.

How to find Alpha Centauri: Alpha Centauri is located at the very bottom of the constellation Centaurus. Also, in order to find this three-star system, you can first find the constellation of the Southern Cross in the starry sky, then mentally continue the horizontal line of the cross towards the west, and you will first stumble upon the star Hadar, and a little further Alpha Centauri will shine brightly.

4. Arcturus / Arcturus

The first three stars in our ranking are mostly visible in the southern hemisphere. Arcturus is the brightest star in the northern hemisphere. It is noteworthy that, given the binary nature of the Alpha Centauri system, Arcturus can be considered the third brightest star in the Earth's night sky, since it surpasses the brightest star in the Alpha Centauri system, Centauri A (-0.05m versus -0.01m) in brightness.

Arcturus, also known as the "Guardian of the Bear", is an integral satellite of the constellation Ursa Major (Ursa Major), and is very clearly visible in the northern hemisphere of the Earth (in Russia it is visible almost everywhere). Arcturus got its name from the Greek word "arktos", which means "bear".

Arcturus belongs to the type of stars called "orange giants", its mass is twice the mass of our Sun, while the "Guardian of the Bear" bypasses ours in luminosity. daylight 215 times. Light from Arcturus needs to travel 37 Earth years to reach Earth, so when we observe this star from our planet, we see what it was like 37 years ago. The brightness of the glow in the night sky of the Earth "Guard Bear" is -0.04m.

It is noteworthy that Arcturus is in the last stages of his stellar life. Due to the constant struggle between gravity and the pressure of the star, the Bear Guard is today 25 times the diameter of our Sun.

Ultimately, the outer layer of Arcturus will disintegrate and turn into a planetary nebula, similar to the well-known Ring Nebula (M57) in the constellation Lyra. After that, Arcturus will turn into a white dwarf.

It is noteworthy that in the spring, using the above method, you can easily find the brightest star in the constellation Virgo, Spica / Spica. To do this, after you find Arcturus, you just need to continue the arc of the Big Dipper further.

How to find Arcturus: Arcturus is the alpha (i.e. the brightest star) of the spring constellation Bootes. To find the "Guardian of the Bear", it is enough to first find the Big Dipper (Big Dipper) and mentally continue the arc of its handle until you stumble upon a bright orange star. This will be Arcturus, a star that forms, in the composition of several other stars, the figure of a kite.

5. Vega / Vega

The name "Vega" comes from Arabic and means "soaring eagle" or "soaring predator" in Russian. Vega is the brightest star in the constellation Lyra, also home to the equally famous Ring Nebula (M57) and the star Epsilon Lyra.

Ring Nebula (M57)

The Ring Nebula is a luminous shell of gas, somewhat similar to a smoke ring. Presumably this nebula was formed after the explosion of an old star. Epsilon Lyrae, in turn, is a double star, and this can even be seen with the naked eye. However, looking at this double star, even through a small telescope, you can see that each individual star also consists of two stars! That is why Epsilon Lyrae is often referred to as a "double double" star.

Vega is a hydrogen-burning dwarf star, 54 times brighter than our Sun in brightness, while exceeding it in mass by only 1.5 times. Vega is located 25 light-years from the Sun, which is relatively small by cosmic standards, its apparent magnitude in the night sky is 0.03m.

In 1984, astronomers discovered a disk of cold gas surrounding Vega - the first of its kind - extending from the star to a distance of 70 astronomical units (1AU = the distance from the Sun to the Earth). By the standards solar system the margins of such a disk would end approximately at the borders of the Kuiper Belt. This is very important discovery, because it is believed that a similar disk was also present in our solar system at the stages of its formation, and served as the beginning of the formation of planets in it.

It is noteworthy that astronomers have found "holes" in the disk of gas surrounding Vega, which may well indicate that planets have already formed around this star. This discovery attracted the American astronomer and writer Carl Sagan to choose Vega as the source of intelligent extraterrestrial signals transmitted to Earth in his first science fiction novel, Contact. Note that in real life, such contacts have never been recorded.

Together with bright stars Altair and Deneb, Vega forms the famous Summer Triangle, an asterism that symbolically signals the beginning of summer in the northern hemisphere of the Earth. This area is ideal for viewing with any size telescope on warm, dark, cloudless summer nights.

Vega is the first star in the world to be photographed. This event took place on July 16, 1850, an astronomer at Harvard University acted as a photographer. Note that stars dimmer than the 2nd apparent magnitude were generally not available for photography, with the equipment available at that time.

How to find Vega: Vega is the second brightest star in the northern hemisphere, so finding it in the starry sky is not difficult. Most in a simple way search for Vega, there will be an initial search for the asterism "Summer Triangle". With the beginning of June in Russia, already with the onset of the first twilight, the “Summer Triangle” is clearly visible in the sky to the southeast. The upper right corner of the triangle forms just the same Vega, the upper left - Deneb, well, Altair shines below.

6. Capella / Capella

Capella is the brightest star in the constellation Auriga, the sixth brightest star in the Earth's night sky. If we talk about the northern hemisphere, here Capella takes an honorable third place among the brightest stars.

At the moment, it is known that Capella is an incredible system of 4 stars: 2 stars are similar yellow G-class giants, the second pair are much dimmer stars of the “red dwarf” class. The brighter of the two yellow giant, named Aa, is 80 times brighter and almost three times as massive as our star. The dimmer yellow giant, known as Ab, is 50 times brighter than the Sun and 2.5 times heavier. If you combine the glow of these two yellow giants, then they will surpass our Sun in this indicator by 130 times.

Comparison of the Sun (Sol) and the stars of the Capella system

The Capella system is located at a distance of 42 light years from us, and its apparent magnitude is 0.08m.

If you are at 44 degrees north latitude (Pyatigorsk, Russia) or even further north, you can observe the Chapel throughout the night: in these latitudes, it never sets beyond the horizon.

Both yellow giants are at the last stage of their lives, and very soon (by cosmic standards) will turn into a pair of white dwarfs.

How to find the Chapel: If you mentally draw a straight line through the two upper stars that form the bucket of the constellation Ursa Major, you will simply inevitably stumble upon the bright star Capella, which is part of the non-standard pentagon of the constellation Auriga.

7. Rigel / Rigel

In the lower right corner of the constellation Orion, the inimitable star Rigel shines regally. According to ancient legends, it was in the place where Rigel shines that the hunter Orion was bitten during a short fight with the insidious Scorpio. Translated from Arabic, "crossbar" means "foot".

Rigel is a multi-star system in which the brightest star is Rigel A, a blue supergiant, 40,000 times brighter than the Sun. Despite its distance from our celestial body of 775 light years, it shines in our night sky with an indicator of 0.12m.

Rigel is located in the most impressive, in our opinion, winter constellation, the invincible Orion. This is one of the most recognizable constellations (except perhaps the Big Dipper constellation), since Orion is very easy to identify by the shape of the stars, which resembles the outlines of a person: three stars located close to each other symbolize the hunter's belt, while four stars located at the edges represent his arms and legs.

If you observe Rigel through a telescope, you can see his second companion star, the apparent magnitude of which is only 7m.

The mass of Rigel is 17 times the mass of the Sun, and it is likely that after some time it will turn into a supernova and our galaxy will be illuminated by an incredible light from its explosion. However, it may also happen that Rigel can turn into a rare oxygen-neon white dwarf.

Note that in the constellation of Orion there is another very interesting place: the Great Nebula of Orion (M42), it is located in the lower part of the constellation, under the so-called hunter's belt, and new stars still continue to be born here.

How to find Rigel: First you need to find the constellation Orion (in Russia it is observed throughout the territory). In the lower left corner of the constellation, the star Rigel will shine brightly.

8. Procyon / Procyon

The star Procyon is located in the small constellation Canis Minor. This constellation depicts the smaller of the two hunting dogs belonging to the hunter Orion (the larger, as you might guess, symbolizes the constellation Canis Major).

Translated from Greek, the word “procyon” means “ahead of the dog”: in the northern hemisphere, Procyon is a harbinger of the appearance of Sirius, which is also called the “Dog Star”.

Procyon is a yellow-white star, 7 times more luminous than the Sun, while in size it is only twice as big as our star. As in the case of Alpha Centauri, Procyon shines so brightly in our night sky due to its proximity to the Sun - 11.4 light-years separate our luminary and a distant star.

Procyon is at the end of its life cycle: now the star is actively converting the remaining hydrogen into helium. Now this star is twice the diameter of our Sun, making it one of the brightest celestial bodies in the Earth's night sky at a distance of 20 light years.

It is worth noting that Procyon, together with Betelgeuse and Sirius, forms the well-known and recognizable asterism, the Winter Triangle.

Procyon A and B and their comparison with the Earth and the Sun

A white dwarf star revolves around Procyon, which was visually discovered in 1896 by the German astronomer John Schieber. At the same time, conjectures about the existence of a companion in Procyon were put forward as early as 1840, when another German astronomer, Arthur von Auswers, noticed some inconsistencies in the movement of a distant star, which with a high degree of probability could only be explained by the presence of a large and dim body.

The dimmer companion, named Procyon B, is one-third the size of Earth and has a mass of 60% that of the sun. The brighter star in this system has since been called Procyon A.

How to find Procyon: To begin with, we find the well-known constellation Orion. In this constellation, in the upper left corner, there is the star Betelgeuse (also included in our rating), mentally drawing a straight line from it in a westerly direction, you will certainly stumble upon Procyon.

9. Achernar / Achernar

Achernar, translated from Arabic means "end of the river", which is quite natural: this star is the most southern point of the constellation bearing the name of the river from ancient Greek mythology, Eridanus.

Achernar is the hottest star in our TOP 10 rating, its temperature varies from 13 to 19 thousand degrees Celsius. This star is also incredibly bright: in terms of luminosity, it is about 3150 times brighter than our Sun. With an apparent magnitude of 0.45m, light from Achernar takes 144 Earth years to reach our planet.

The constellation Eridani with its extreme point, the star Achernar

Achernar is quite close in apparent magnitude to the star Betelgeuse (number 10 in our rating). However, Achernar is generally ranked 9th in the list of brightest stars, as Betelgeuse is a variable star whose apparent magnitude can drop from 0.5m to as low as 1.2m, as it did in 1927 and 1941.

Achernar is a massive class B star, eight times the mass of our Sun. Now it is actively converting its hydrogen into helium, which will eventually turn it into a white dwarf.

It is noteworthy that for a planet of the class of our Earth, the most comfortable distance from Achernar (with the possibility of the existence of water in liquid form) would be a distance of 54-73 astronomical units, that is, in the Solar System it would be beyond the orbit of Pluto.

How to find Achernar: on the territory of Russia, alas, this star is invisible. In general, for a comfortable observation of Achernar, you need to be south of the 25th degree of North latitude. To find Achernar, mentally draw a straight line in a southerly direction through the stars Betelgeuse and Rigel. The first super-bright star you will see will be Achernar.

10. Betelgeuse / Betelgeuse

Do not think that the importance of Betelgeuse is as low as its position in our ranking. A distance of 430 light-years hides from us the true scale of the super-giant star. However, even at such a distance, Betelgeuse continues to sparkle in the earth's night sky with an indicator of 0.5m, while this star is 55 thousand times brighter than the Sun.

Betelgeuse in Arabic means "armpit hunter."

Betelgeuse marks the eastern shoulder of the mighty Orion from the constellation of the same name. Also, Betelgeuse is also called Alpha Orion, that is, in theory, it should be the brightest star in its constellation. However, in fact, the brightest star in the constellation Orion is the star Rigel. This oversight, most likely, was due to the fact that Betelgeuse is a variable star (a star that changes its brightness from time to time). Therefore, it is likely that at the time when Johannes Bayer estimated the brightness of these two stars, Betelgeuse shone brighter than Rigel.

If Betelgeuse replaced the sun in the solar system

The star Betelgeuse is a red supergiant of class M1, its diameter is 650 times the diameter of our Sun, while in mass it is only 15 times heavier than our celestial body. If we imagine that Betelgeuse becomes our Sun, then everything that is before the orbit of Mars will be absorbed by this giant star!

When you start observing Betelgeuse, you will see a star at the sunset of your long life. Its huge mass suggests that it is most likely that it converts all of its elements into iron. If this is so, then in the near future (by cosmic standards) Betelgeuse will explode and turn into a supernova, while the explosion will be so bright that in terms of its glow power it can be compared with the glow of a crescent moon visible from Earth. The birth of a supernova will leave behind a dense neutron star. According to another theory, Betelgeuse may turn into a rare type of neon-oxygen dwarf star.

How to find Betelgeuse: First you need to find the constellation Orion (in Russia it is observed throughout the territory). In the upper right corner of the constellation, the star Betelgeuse will shine brightly.

People have always admired starry sky. Even in the Stone Age, living in caves and dressed in skins, at night they raised their heads to the sky and admired the glowing lights.

Today the stars still attract our eyes. We know well that the brightest of them is the Sun. But what are the others called? What are the brightest stars besides the Sun?

1 Sirius

Sirius is the brightest star in the night sky. It is not much higher (only 22 times), but due to its proximity to the Earth, it is more noticeable than others. The star can be seen from almost any corner of the globe, except for the northern regions.

In 1862, astronomers discovered that Sirius had a companion star. Both of them revolve around a single center of mass, but only one of them is visible from the Earth - Sirius A. According to scientists, the star is gradually approaching the Sun. Its speed is 7.6 km / s, so over time it will become even brighter.

2. Canopus

Canopus is in the constellation Carina and is the second brightest after Sirius. It belongs to the supergiants, exceeding the Sun in radius by 65 times.

Among all the stars located at a distance of 700 light years from Earth, Canopus has the highest luminosity, but due to its remoteness, it does not shine as brightly as Sirius. Once, before the invention of the compass, sailors used it as a guiding star.

3. Toliman

Toliman is another name for Alpha Centauri. In fact, it is a binary system with stars A and B, but these stars are so close to each other that they cannot be distinguished with the naked eye. The third brightest in the sky is one of them - Alpha Centauri A.

In the same system there is another star - Proxima Centauri, but usually it is considered separately, and in terms of brightness it is not even included in the 25 stars with the highest luminosity.

4. Arcturus

Arcturus belongs to the orange giants and shines brighter than other stars included with it. In different regions of the Earth, it can be seen at different times of the year, but in Russia it is always visible.

According to the observations of astronomers, Arcturus is a variable star, that is, changing its brightness. Every 8 days, its brightness varies by 0.04 magnitude, which is explained by the pulsation of the surface.

5. Vega

The fifth brightest star is included in the constellation Lyra and is the most studied after the Sun. Vega is located at a small distance from the solar system (only 25 light years) and is visible from anywhere on the planet, with the exception of Antarctica and the northern regions of North America.

Around Vega is a disk of gas and dust, which, under the influence of its energy, emits infrared rays.

6. Chapel

From an astronomical point of view, the star is interesting for its binary system. Capella is two giant stars, 100 million kilometers apart. One of them called Chapel Aa is old and gradually begins to fade.

The second one, Capella Ab, still shines quite brightly, but, according to scientists, the processes of helium synthesis have already ended in it. Sooner or later, the shells of both stars will expand and touch each other.

7. Rigel

The luminosity of Rigel is 130 thousand times greater than the Sun. This is one of the most powerful stars in the Milky Way, but due to its remoteness from the solar system (773 light years), it is only seventh in brightness.

Like Arcturus, Rigel is considered a variable star and changes its brightness at intervals of 22 to 25 days.

8. Procyon

Procyon's distance from Earth is only 11.4 light years. Its system includes two stars - Procyon A (bright) and Procyon B (dim). The first is a yellow subgiant and shines about 7.5 times brighter than the Sun. Due to its age, over time it will begin to expand and will shine much better.

It is believed that sooner or later it will increase to 150 times its current size, and then take on an orange or red color.

9. Achernar

In the list of the 10 brightest stars in the sky, Achernar takes only ninth place, but at the same time she is the hottest and bluest. The star is located in the constellation Eridani and shines 3000 times brighter than the Sun.

Interesting feature Achernara is a very fast rotation around its axis, as a result of which it has an elongated shape.

10. Betelgeuse

Betelgeuse's maximum luminosity is 105,000 times that of the Sun, but it's about 640 light-years away from the solar system, so it's not as bright as the previous nine stars.

Due to the fact that the brightness of Betelgeuse gradually decreases from the center to the surface, scientists still cannot calculate its diameter.

Astronomy

Translation

Do you know all of them, as well as the reasons for their brightness?

I am hungry for new knowledge. The point is to learn every day, and become brighter and brighter. That is the essence of this world.
- Jay Z

When you imagine the night sky, you most likely think of thousands of stars twinkling on a black blanket of night, something that can only truly be seen away from cities and other sources of light pollution.

But those of us who can't watch such a spectacle on a periodic basis are overlooking the fact that stars seen from urban areas with high light pollution look different than they do when viewed in dark conditions. Their color and relative brightness immediately separate them from their neighboring stars, and each of them has its own story.

Residents of the northern hemisphere can probably immediately recognize the Big Dipper or the letter W in Cassiopeia, while in the southern hemisphere the most famous constellation has to be the Southern Cross. But these stars are not among the ten brightest!

Milky Way near the Southern Cross

Every star has its own life cycle to which she has been attached since birth. In the formation of any star, the dominant element will be hydrogen - the most abundant element in the universe - and its fate is determined only by its mass. Stars with a mass of 8% of the mass of the sun can ignite a nuclear fusion reaction in the core, fusing helium from hydrogen, and their energy gradually moves from the inside out and pours out into the universe. Low-mass stars are red (due to low temperatures), dim, and burn their fuel slowly—the longest-lived stars are destined to burn for trillions of years.

But the more a star gains mass, the hotter its core, and the larger the region in which nuclear fusion takes place. By the time it reaches the solar mass, the star falls into class G, and its lifetime does not exceed ten billion years. Double the solar mass and you have an A star, bright blue, and less than two billion years old. And the most massive stars, classes O and B, live only a few million years, after which they run out of hydrogen fuel in the core. Not surprisingly, the most massive and hottest stars are also the brightest. A typical class A star can be 20 times brighter than the Sun, and the most massive - tens of thousands of times!

But no matter how a star begins life, the hydrogen fuel in its core ends.

And from that moment on, the star begins to burn heavier elements, expanding into a giant star, colder, but also brighter than the original one. The giant phase is shorter than the hydrogen burning phase, but its incredible brightness makes it visible from much long distances than those from which the original star was visible.

Considering all this, let's move on to the ten brightest stars in our sky, in order of increasing brightness.

10. Achernar. A bright blue star, seven times the mass of the Sun and 3,000 times as bright. This is one of the fastest rotating stars known to us! It rotates so fast that its equatorial radius is 56% greater than the polar one, and the temperature at the pole - since it is much closer to the core - is 10,000 K more. But it is quite far from us, at 139 light years.

9. Betelgeuse. A red giant from the constellation of Orion, Betelgeuse was a bright and hot class O star until it ran out of hydrogen and switched to helium. Despite low temperature at 3500 K, it is more than 100,000 times brighter than the Sun, which is why it is among the ten brightest, despite being 600 light years away. In the next million years, Betelgeuse will go supernova, and temporarily become the brightest star in the sky, possibly visible during the day.

8. Procyon. The star is very different from the ones we have considered. Procyon is a modest F-class star, only 40% larger than the Sun, and is on the verge of running out of hydrogen in its core - that is, it is a subgiant in the process of evolution. It is about 7 times brighter than the Sun, but is only 11.5 light-years away, so it can be brighter than almost all but seven of the stars in our sky.

7. Rigel. In Orion, Betelgeuse is not the brightest of the stars - this distinction is awarded to Rigel, a star even more distant from us. It's 860 light years away, and at just 12,000 degrees, Rigel isn't a main sequence star - it's a rare blue supergiant! It is 120,000 times brighter than the Sun, and shines so brightly not because of its distance from us, but because of its own brightness.

6. Chapel. This is a strange star, because, in fact, these are two red giants with a temperature comparable to the sun, but each of them is about 78 times brighter than the Sun. At 42 light-years away, it's the combination of its own brightness, its relatively small distance, and the fact that there are two of them that allows Capella to be on our list.

5. Vega. The brightest star from the Summer-Autumn Triangle, the home of aliens from the movie "Contact". Astronomers used it as a standard "zero magnitude" star. It is only 25 light-years away, belongs to the main sequence stars, and is one of the brightest class A stars known to us, as well as quite young, only 400-500 million years old. At the same time, it is 40 times brighter than the Sun, and the fifth brightest star in the sky. And of all the stars in the northern hemisphere, Vega is second only to one star...

4. Arcturus. The orange giant, on the evolutionary scale, is somewhere between Procyon and Capella. This is the brightest star in the northern hemisphere, and it is easy to find it by the "handle" of the Big Dipper bucket. It is 170 times brighter than the Sun, and following the evolutionary path, it can become even brighter! It is only 37 light-years away, and only three stars are brighter than it, all located in the southern hemisphere.

3. Alpha Centauri. This is a triple system in which the main member is very similar to the Sun, and itself is dimmer than any of the ten stars. But the Alpha Centauri system consists of the stars closest to us, so its location affects its apparent brightness - after all, it is only 4.4 light-years away. Not at all like #2 on the list.

2. Canopus. supergiant white color, Canopus is 15,000 times brighter than the Sun, and is the second of the brightest stars in the night sky, despite being 310 light-years away. It is ten times more massive than the Sun and 71 times larger - it is not surprising that it shines so brightly, but it could not reach the first place. The brightest star in the sky is...

1 Sirius. It is twice as bright as Canopus and northern hemisphere observers can often see it rising behind the constellation Orion in winter. It often twinkles because its bright light can penetrate the lower atmosphere better than the light of other stars. It is only 8.6 light-years away, but it is a Class A star, twice as massive and 25 times as luminous as the Sun.

It may surprise you that the first on the list are not the brightest or closest stars, but rather combinations of enough brightness and close enough distance to shine the brightest. Stars twice as far away are four times less bright, so Sirius shines brighter than Canopus, which shines brighter than Alpha Centauri, and so on. Interestingly, class M dwarf stars, to which three out of every four stars in the universe belong, are not on this list at all.

What can be learned from this lesson: sometimes the things that seem most prominent and most obvious to us turn out to be the most unusual. Common things can be much more difficult to find, but this means that we should improve our methods of observation!

For the first time, the stars began to be distinguished by brightness in the II century BC by the ancient Greek astronomer Hipparchus. He singled out 6 degrees in the glow and introduced the concept of magnitude. The German astronomer Johann Bayer at the beginning of the 17th century introduced the brightness of the stars in the constellations with the letters of the alphabet. The brightest luminaries for the human eye were called α of such and such a constellation, β - the next in brightness, etc.

The hotter the star, the more light it emits.

Blue stars are the most luminous. Less bright whites. Yellow stars have an average luminosity, and red giants are considered the dimmest. The luminosity of a celestial body is a variable value. For example, in, dated July 4, 1054, it tells about a star in the constellation Taurus so bright that it was visible even during the day. Over time, it began to fade, and after a year it could no longer be seen with the naked eye.

Now in the constellation of Taurus, you can observe the Crab Nebula - a trace after the explosion of a supernova. In the center of the nebula, astronomers have discovered a source of powerful radio emission - a pulsar. This is all that remains of the supernova explosion observed in 1054.

The brightest stars in the sky

The brightest stars in the Northern Hemisphere are Deneb in the constellation Cygnus and Rigel in the constellation Orion. They exceed the luminosity of the Sun by 72,500 and 55,000 times, respectively. They are at a distance of 1600 and 820 light years from Earth. Another star of the North - Betelgeuse - is also located in the constellation of Orion. It emits 22,000 times more light than the Sun.

Most of the brightest stars in the Northern Hemisphere can be observed in the constellation of Orion.

Sirius, in the constellation Canis Major, is the brightest star visible from Earth. It can be observed in the Southern Hemisphere. Sirius is only 22.5 times brighter than the Sun, but the distance to this star is small by cosmic standards - 8.6 light years. The polar star in the constellation Ursa Minor, like 6000 Suns, but it is 780 light-years away from us, so it looks dimmer than close Sirius.

In the constellation Taurus is a star with the astronomical name UW CMa. You can only see her. This blue star is distinguished by its gigantic density and small spherical magnitude. It is 860,000 times brighter than the Sun. This unique celestial body is considered the brightest object in the observable part of the Universe.

Sources:

brightest stars in the northern hemisphere

The starry sky is mesmerizing. It amazed people with its greatness from time immemorial. From the realization that the Earth is just a grain of sand of the Universe, the heart stops. How many in the sky, no one can say with accuracy, you can only find out which star appears first.

Instruction

The first bright spot in the evening sky is Venus, although it is not a star at all. If you want to see it, then immediately after sunset, look to the west. Of course, it all depends on the weather conditions and time of year, but most often it is Venus that can be observed first. This is the second planet from the Sun, some call it " evening Star". Even with the onset of night, it stands out quite brightly against the background of other stars, it is difficult not to notice it. However, you can observe Venus for a short time, only a couple of hours, by the middle of the night it seems to disappear. Few people know, but Venus can also be called a “morning star”, because when they have already gone out, this bright point continues to shine against the backdrop of dawn. People have sung Venus since time immemorial, deified it, praised it in poems, portrayed it on canvases. Yes, Venus is a planet, but for many, even today, as in ancient times, it remains the "evening star".

Of all the stars, Sirius shines brightest for us, which is why it can be seen in the evening sky. The fact is that Sirius is located very close to the Earth, of course, if we talk on a cosmic scale. The distance from the planet Earth to the legendary star is only nine light years. However, in fact, Sirius is an ordinary star, no different from others. Only because of the small distance, Sirius seems to be a majestic bright giant against the background of other, more distant stars.

Translation

Do you know all of them, as well as the reasons for their brightness?

I am hungry for new knowledge. The point is to learn every day, and become brighter and brighter. That is the essence of this world.
- Jay Z

Milky Way near the Southern Cross

Each star has its own life cycle, to which it is tied from the moment of birth. In the formation of any star, the dominant element will be hydrogen - the most abundant element in the universe - and its fate is determined only by its mass. Stars with a mass of 8% of the mass of the sun can ignite a nuclear fusion reaction in the core, fusing helium from hydrogen, and their energy gradually moves from the inside out and pours out into the universe. Low-mass stars are red (due to low temperatures), dim, and burn their fuel slowly—the longest-lived stars are destined to burn for trillions of years.

But no matter how a star begins life, the hydrogen fuel in its core ends.

And from that moment on, the star begins to burn heavier elements, expanding into a giant star, colder, but also brighter than the original one. The giant phase is shorter than the hydrogen burning phase, but its incredible brightness makes it visible from far greater distances than the original star was visible from.

Considering all this, let's move on to the ten brightest stars in our sky, in order of increasing brightness.

9. Betelgeuse. A red giant from the constellation of Orion, Betelgeuse was a bright and hot class O star until it ran out of hydrogen and switched to helium. Despite its low temperature of 3500 K, it is more than 100,000 times brighter than the Sun, which is why it is among the ten brightest, despite being 600 light years away. In the next million years, Betelgeuse will go supernova, and temporarily become the brightest star in the sky, possibly visible during the day.

2. Canopus. A white supergiant, Canopus is 15,000 times brighter than the Sun and is the second brightest star in the night sky despite being 310 light-years away. It is ten times more massive than the Sun and 71 times larger - it is not surprising that it shines so brightly, but it could not reach the first place. The brightest star in the sky is...