The brightest star in the night sky. Names of stars and constellations in the sky

> The most bright Star in the sky

Sirius is the brightest star: the meaning of the name Alpha Big Dog, characteristic and description with photo, distance from the Earth, detection, list of the brightest stars.

Among all the stars known to us, the brightest in the sky is Sirius, which is also called the “Star of the Dog”. Official name- Alpha Canis Major, located in the constellation of the same name.

Sirius is a binary system with a main sequence (A) star whose apparent magnitude reaches -1.46. It is 8.7 light years away from us and is closest to Earth.

In 1844, Friedrich Bessel noticed that the orbital path of Sirius A is a bit like a wave, which means there may be a weak satellite nearby. Alvan Clark confirmed this in 1862. We are talking about Sirius B - a white dwarf that can be seen in a large telescope (it has little effect on the overall brightness of the system).

But there are other stars near us, why is Sirius the brightest? The fact is that most stars belong to the category of red dwarfs. They are not only small, but also dull. In fact, the closest red dwarf is Proxima Centauri. It's M-type less G-type(Sun). The brightest is A-type (Sirius).

The starry sky can captivate for life thanks to its bright lights. Even with the naked eye, you can see that some objects shine brighter than others. Scientists measure the brightness of celestial bodies using a scale. The smaller the object itself, the brighter it will be.

List of brightest stars in the sky

We know which star is the brightest for an earthly observer. However, other bright celestial bodies can be found in space. You will be able to admire most bright stars in the sky and their "apparent magnitudes" (as they are seen towards the Earth). Use our online star chart to find them yourself with a telescope.

Achernar

The star Achernar is located in the constellation Eridani and is 69 light years away from us. The apparent value is 0.46, and the absolute value is -1.3.

Procyon is located 11.4 light years in the constellation Canis Minor. The apparent value is 0.38, while the absolute value is 2.6.

Rigel is located 1400 light years away in the constellation of Orion. The apparent value is 0.12, and the absolute value reaches -8.1.

The chapel is located in the constellation Auriga (41 light years). The apparent magnitude is 0.08, and the absolute value is 0.4.

The star Vega is located in the constellation Lyra (25 light years). The apparent value is 0.03, and the absolute value is 0.6.

Arcturus is in the constellation Bootes (34 light years). The apparent value is -0.04, and the absolute value is 0.2.

Alpha Centauri is the third brightest in the entire sky. It is located in the Alpha Centauri system and is 4.3 light years distant. The apparent value reaches -0.27, and the absolute value - 4.4.

The star Canopus is located in the constellation Carina (74 light years). The apparent value is -0.72, and the absolute value reaches -2.5.

Lives in the constellation Canis Major. It is 8.6 light years away from us. The apparent value is -1.46, and the absolute value is 1.4.

The sun is the closest star to us, 93 million miles away. The apparent magnitude is -26.72, and the absolute value is 4.2.

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 at the time of Hipparchus there were no telescopes yet, therefore, looking at the sky with the naked eye, the ancient astronomer could only distinguish stars of the 6th magnitude (the least luminous) by 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 more precise light-measuring instruments, astronomers have decided to use decimal fractions for stellar magnitudes—2.75m, for example—rather than just rough numbers of 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 capital letter 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 located in the constellation Canis Major, which is why it is often referred to as the Dog Star. AT 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.

snapshot Hubble telescope: Sirius A (brighter and more massive star) and Sirius B (lower 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 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 turn into one of the largest white dwarfs in the galaxy, and its size may even be enough to completely process all of its carbon reserves, which will make it very rare view neon-oxygen white dwarfs. 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, two of the brightest stars in the Alpha Centauri system can be seen.

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 in terms of luminosity, the "Guardian of the Bear" bypasses our daytime star by 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 25 times the diameter of our Sun today.

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 of the 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 the 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 yellow G-class giants similar to each other, the second pair are much dimmer stars of the “red dwarf” class. The brighter of the two, the yellow giant, named Aa, is 80 times brighter and nearly 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 on 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 outline 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 dimensions 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 in the twilight 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 Ausvers, 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 fainter companion has been named Procyon B and is three times smaller size Earth, and its mass is 60% 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.

Constellation Eridanus 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 as the 9th brightest star in the rankings, 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 enormous mass suggests that it is most likely transmuting 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 right upper corner constellation, the star Betelgeuse will shine brightly.

10

• Alternative name:α Leo
• Apparent magnitude: 1,35
• Distance to the Sun: 77.5 St. years

The brightest star in the constellation Leo and one of the brightest stars in the night sky. Regulus is at a distance of about 77.5 light year from the solar system. From Latin, the name is translated as "prince". In Arabic, it sounds like Kalb Al-Assad (قلب الأسد), which means "the heart of a lion." Sometimes the translation of this name is found in Latin - Cor Leonis. Regulus is considered the last in the list of stars of the first magnitude, since the next brightest star, Adara, has a magnitude of 1.50m, which makes it a star of the second magnitude.

Regulus is about 3.5 times more massive than the Sun. It is a young star, only a few hundred million years old. It rotates extremely fast, with a rotation period of only 15.9 hours, which makes its shape highly flattened (the equatorial radius is a third larger than the polar one) and similar to a pumpkin. This results in gravitational darkening, in which the poles of a star are significantly (50%) hotter and five times brighter (per unit surface area) than its equator. If it were only spinning 14% faster, the centripetal gravitational force would not be enough to keep the star from disintegrating. The axis of rotation of Regulus almost coincides with the direction of motion of the star in space. It was also found that the axis of rotation is perpendicular to the line of sight. This means that we are watching Regulus from the edge.

9

• Alternative name:α Cygnus
• Apparent magnitude: 1,25
• Distance to the Sun:~1550 St. years

The name "Deneb" comes from the Arabic dheneb ("tail"), from the phrase ذنب الدجاجة dhanab ad-dajājat, or "hen's tail". This star is the brightest in the constellation Cygnus, ranks ninth in brightness among the stars of the northern hemisphere and twentieth among the stars of both hemispheres. Together with the stars Vega and Altair, Deneb forms the "summer-autumn triangle", which is visible in the Northern Hemisphere during the summer and autumn months.

Deneb is one of the largest and most powerful stars known to science. Diameter of Deneb approx. equal to the diameter earth orbit (≈300 million kilometers). Deneb has an absolute magnitude of −6.5m, making Deneb the most powerful of the 25 brightest stars in the sky.

The exact distance to Deneb remains a matter of controversy to this day. Most stars at this distance from Earth are not visible to the naked eye, and can only be identified from a catalog, provided they are known at all. On various Internet resources, you can find values ​​\u200b\u200bfrom 1340 to 3200 light years. The latest parallax refinements give a distance estimate of 1340 to 1840 light years, with a most likely value of 1550 light years.

If Deneb were a point source of light at the same distance from the Earth as the Sun, then it would be much brighter than most industrial lasers. In one Earth day, it emits more light than the Sun in 140 years. If it were at the same distance as Sirius, it would be brighter than the full moon.

The mass of Deneb is considered equal to 15-25 solar. Since Deneb is a white supergiant, due to its high temperature and mass, we can conclude that its lifespan is short, and in a couple of million years it will go supernova. Thermonuclear reactions involving hydrogen have already ceased in its core.

Every year, Deneb loses up to 0.8 millionth of the solar mass in the form of a stellar wind. This is one hundred thousand times greater than that of the Sun.

8

• Alternative name:β Gemini
• Apparent magnitude: 1,14
• Distance to the Sun: 40 St. years

This star was named after one of the two Dioscuri brothers - Polydeuces ("Pollux" is his Latinized name). In the drawing of the constellation Pollux is located on the head of the southern twin.

According to the classification of Johann Bayer, the star is labeled as β Gemini, despite the fact that it is the brightest in the constellation. "Alpha" was also named the star Castor with an apparent magnitude of 1.57. It so happened due to the fact that visually these two stars are almost equally bright, and just for such a case, when two stars of the same brightness are located close to each other, there is a second Bayer classification criterion (the first criterion is brightness) - priority is given to the more northern star.

Pollux is a small orange star that belongs to the spectral type K0 IIIb. Its luminosity is only 32 times that of our Sun. The mass of Pollux is 1.86 solar masses. Based on these data, it becomes clear that such a celestial body could not be included in the list of the brightest stars in the sky, if not for its close quarters to our planet. According to 2011 data, the distance from Pollux to Earth is only 40 light years, which is not so much by the standards of space.

The only thing Pollux boasts of is its radius. According to the latest data, its radius exceeds the radius of our Sun by eight times. However, it is believed that it will gradually increase as Pollux slowly transforms into a red giant. Astronomical calculations suggest that the star's supply of helium will run out in about 100 million years, after which Beta Gemini will turn into a white dwarf.

In 2006, a team of astronomers confirmed that Pollux had an exoplanet.

7

• Alternative name:α Taurus
• Apparent magnitude: 0.85 (variable)
• Distance to the Sun: 65 St. years

Aldebaran is the brightest Zyezd among all the stars of the zodiac constellations. The name comes from the Arabic word الدبران (al-dabarān), meaning "follower" - a star in the night sky makes its way after the Pleiades. Because of its position in the head of Taurus, it was called the Eye of Taurus (lat. Oculus Taurī). The names Paliliy and Lamparus are also known.

With an apparent magnitude of 0.85, Aldebaran is the 14th brightest star in the night sky. Its absolute magnitude is -0.3, and the distance to Earth is 65 light years.

Aldebaran has a spectral type of K5III, a surface temperature of 4010° Kelvin, and a luminosity 425 times that of the Sun. The star has a mass of 1.7 solar masses and a diameter that is 44.2 times that of the sun.

Aldebaran is one of the simplest stars to be found in the night sky, partly because of its brightness and partly because of its spatial arrangement in relation to one of the most visible asterisms in the sky. If you follow the three stars in Orion's belt from left to right (northern hemisphere) or right to left (south), the first bright star you find as you continue along this line is Aldebaran.

6

• Alternative name:α Eagle
• Apparent magnitude: 0,77
• Distance to the Sun: 18 St. years

Altair is one of the closest stars visible to the naked eye. Along with Beta Aquila and Tarazed, the star forms a well-known line of stars sometimes called the Aquila family. Altair forms one of the vertices of the Summer Triangle along with Deneb and Vega.

Altair has an extremely high rotation speed, which reaches 210 kilometers per second at the equator. Thus, one period is about 9 hours. By comparison, the Sun takes just over 25 days to complete one full rotation at the equator. This rapid rotation causes the Altair to be slightly flattened. Its equatorial diameter is 20 percent larger than the polar one.

Altair has a spectral type of A7Vn, a surface temperature of 7500° Kelvin, and a luminosity 10.6 times that of the Sun. Its mass is 1.79 solar masses, and its diameter is 1.9 times greater than that of the Sun.

5

• Alternative name:α Orionis
• Apparent magnitude: 0.50 (variable)
• Distance to the Sun: 495 - 640 St. years

Betelgeuse is a bright star in the constellation Orion. A red supergiant, a semi-regular variable star whose brightness varies from 0.2 to 1.2 magnitudes. The minimum luminosity of Betelgeuse is 80 thousand times greater than the luminosity of the Sun, and the maximum is 105 thousand times. The distance to the star is, according to various estimates, from 495 to 640 light years. This is one of the largest stars known to astronomers: if it is placed in the place of the Sun, then minimum size it would fill the orbit of Mars, and at the maximum it would reach the orbit of Jupiter.

The angular diameter of Betelgeuse, according to modern estimates, is about 0.055 arcseconds. If we take the distance to Betelgeuse equal to 570 light years, then its diameter will exceed the diameter of the Sun by about 950-1000 times. The mass of Betelgeuse is approximately 13-17 solar masses.

4

• Alternative name:α Small Dog
• Apparent magnitude: 0,38
• Distance to the Sun: 11.46 St. years

To the naked eye, Procyon looks like a single star. In fact, Procyon is a binary star system consisting of a main sequence white dwarf called Procyon A and a faint white dwarf called Procyon B. Procyon looks so bright not because of its luminosity, but because of its proximity to the Sun. The system is located at a distance of 11.46 light years (3.51 parsecs) and is one of our closest neighbors.

The origin of the name Procyon is very interesting. It is based on long observation. Literal translation from Greek " before Dog", more literary -" the harbinger of the dog. The Arabs called him - "Sirius, shedding tears." All names have a direct connection with Sirius, who was worshiped by many ancient peoples. It is not surprising that observing starry sky, they noticed the harbinger of the rising Sirius - Procyon. He appears in the sky 40 minutes earlier, as if running ahead. If you imagine Canis Minor in the picture, then Procyon should be looked for in its hind legs.

Procyon shines like 8 of our Suns and is the eighth brightest star in the night sky, the luminosity is 6.9 times greater than that of the Sun. The mass of the star is 1.4 times the mass of the Sun, and the diameter is 2 times. It is moving towards the solar system at a speed of 4500 m per second

Finding Procyon is not difficult. To do this, you need to face south. Find the belt of Orion with your eyes and draw a line from the lower star of the belt to the east. You can navigate by the larger constellation Gemini. In relation to the horizon, the Small Dog is below them. And finding Procyon in the constellation Canis is not difficult, because it is the only bright object, and it attracts with its radiance. Since the constellation Canis Minor is equatorial, that is, it rises quite low above the horizon, in different time year it rises in different ways and best time for his observations - winter.

3

• Alternative name:α Aurigae
• Apparent magnitude: 0,08
• Distance to the Sun: 42.6 St. years

Capella is the brightest star in the constellation Auriga, the sixth brightest star in the sky and the third brightest in the sky of the Northern Hemisphere.

Capella (lat. Capella - "Goat"), also Capra (lat. Capra - "goat"), Al Khayot (Arabic العيوق - "goat") - a yellow giant. In the drawing of the constellation, Capella is located on the shoulder of the Auriga. On sky maps, a goat was often drawn on this shoulder of the Charioteer. It is closer to the north celestial pole than any other star of the first magnitude (the North Star is only of the second magnitude) and therefore plays an important role in many mythological tales.

From an astronomical point of view, Capella is interesting in that it is a spectroscopic binary star. Two giant stars of spectral type G, with a luminosity of about 77 and 78 solar, are 100 million km apart (2/3 of the distance from the Earth to the Sun) and rotate with a period of 104 days. The first and fainter component - Capella Aa has already evolved from the main sequence and is at the stage of a red giant, helium burning processes have already begun in the interior of the star. The second and brighter component, Capella Ab, also left the main sequence and is on the so-called “Hertzsprung gap” - a transitional stage in the evolution of stars, in which the thermonuclear fusion of helium from hydrogen in the core has already ended, but helium combustion has not yet begun. Capella is a source of gamma radiation, possibly due to magnetic activity on the surface of one of the components.

The masses of the stars are approximately the same and amount to 2.5 solar masses for each star. In the future, due to the expansion to the red giant, the shells of the stars will expand and, quite likely, will come into contact.

The central stars also have a faint companion, which, in turn, is itself a binary star, consisting of two class M stars - red dwarfs revolving around the main pair in an orbit with a radius of about one light year.

Capella was the brightest star in the sky from 210,000 to 160,000 BC. e. Prior to this, the role of the brightest star in the sky was played by Aldebaran, and after that by Canopus.

2

• Alternative name:α Lyra
• Apparent magnitude: 0.03 (variable)
• Distance to the Sun: b> 25.3 St. years

In summer and autumn, in the night sky, in the northern hemisphere of the celestial sphere, the so-called Great Summer Triangle can be distinguished. This is one of the most famous asterisms. We already know that it includes the familiar Deneb and Altair. They are located "lower", and at the top of the Triangle is Vega - a bright blue star, which is the main one in the constellation Lyra.

Vega is the brightest star in the constellation Lyra, the fifth brightest star in the night sky and the second (after Arcturus) in the Northern Hemisphere. Vega is located at a distance of 25.3 light years from the Sun and is one of the brightest stars in its vicinity (at a distance of up to 10 parsecs). This star has a spectral type of A0Va, a surface temperature of 9600° Kelvin, and its luminosity is 37 times greater than that of the Sun. The mass of the star is 2.1 solar masses, the diameter is 2.3 times that of the Sun.

The name "Vega" comes from an approximate transliteration of the word waqi ("falling") from the phrase Arab. النسر الواقع‎ (an-nasr al-wāqi‘), meaning “falling eagle” or “falling vulture”.

Vega, sometimes referred to by astronomers as "probably the most important star after the Sun," is currently the most studied star in the night sky. Vega was the first star (after the Sun) to be photographed and also the first star to have its emission spectrum determined. Also, Vega was one of the first stars to which the distance was determined by the parallax method. The brightness of Vega for a long time was taken as zero when measuring stellar magnitudes, that is, it was a reference point and was one of the six stars that underlie the scale of UBV photometry (measurement of star radiation in various spectral ranges).

Vega rotates very quickly around its axis, at its equator the rotation speed reaches 274 km / s. Vega spins a hundred times faster, resulting in an ellipsoid of revolution. The temperature of its photosphere is not uniform: the maximum temperature is at the pole of the star, and the minimum temperature is at the equator. At present, from Earth, Vega is observed almost from the pole, and therefore it appears as a bright blue-white star. AT recent times asymmetries have been identified in the disk of Vega, indicating the possible presence of at least one planet near Vega, the size of which may be approximately the size of Jupiter.

In the XII century BC. Vega was the North Star and will be again in 12,000 years. The "change" of the Polar stars is connected with the phenomenon of the precession of the earth's axis.

1

• Alternative name:α Bootes
• Apparent magnitude:−0.05 (variable)
• Distance to the Sun: 36.7 St. years

Arcturus (Alramech, Azimech, Colanza) is the brightest star in the constellation Bootes and the northern hemisphere and the fourth brightest star in the night sky after Sirius, Canopus and the Alpha Centauri system. The apparent magnitude of Arcturus is −0.05m. It enters the Arcturus stellar stream, which, according to Ivan Minchev from the University of Strasbourg and his colleagues, arose as a result of absorption milky way another galaxy about 2 billion years ago.

Arcturus is one of the brightest stars in the sky and therefore easy to find in the sky. Visible anywhere in the world north of 71° S due to its slight northerly declination. To find it in the sky, you need to lay an arc through the three stars of the bucket handle Ursa Major- Aliot, Mizar, Benetnash (Alkaid).

Arcturus is an orange giant of spectral type K1.5 IIIpe. The letters "pe" (from the English peculiar emission) mean that the spectrum of the star is atypical and contains emission lines. In the optical range, Arcturus is more than 110 times brighter than the Sun. From observations it is assumed that Arcturus is a variable star, its brightness changes by 0.04 magnitude every 8.3 days. As with most red giants, the reason for the variability is the pulsation of the star's surface. Radius - 25.7 ± 0.3 solar radii, surface temperature - 4300 K. The exact mass of the star is unknown, but most likely close to solar mass. Arcturus is now at that stage of stellar evolution, in which our daylight star will be in the future - in the red giant phase. The age of Arcturus is about 7.1 billion years (but not more than 8.5 billion)

Arcturus, like more than 50 other stars, is in the Arcturus stream, which brings together stars of different age and metallicity level, moving with similar speed and direction. Given the high speeds of the stars, it is possible that in the past they were captured and absorbed by the Milky Way along with their parent galaxy. Therefore, Arcturus, one of the brightest and relatively close stars to us, may have an extragalactic origin.

The name of the star comes from other Greek. Ἀρκτοῦρος, ἄρκτου οὖρος, "Guardian of the Bear". According to one version of the ancient Greek legend, Arcturus is identified with Arkad, who was placed in the sky by Zeus to protect his mother, the nymph Callisto, who was turned by Hera into a bear (the constellation Ursa Major). According to another version, Arkad is the constellation of Bootes, the brightest star of which is Arcturus.

In Arabic, Arcturus is called Haris-as-sama, "keeper of the heavens" (see Haris).

In Hawaiian, Arcturus is called Hokulea (gav. Hōkūle’a) - “star of happiness”, in the Hawaiian Islands it culminates almost exactly at its zenith. Ancient Hawaiian navigators relied on its height when they sailed to Hawaii.

10

• Alternative name:α Southern Fish
• Apparent magnitude: 1,16
• Distance to the Sun: 25 St. years

The brightest star in the constellation Southern Pisces and one of the brightest stars in the night sky. The name of the star means "mouth of the whale" in Arabic.

Fomalhaut is considered a relatively young star, with an age of 200 to 300 million years and an estimated lifespan of a billion years. The temperature on the surface of the star is about 8500 degrees Kelvin. Fomalhaut is 2.3 times heavier than the Sun, the luminosity is 16 times greater, and the radius is 1.85 times. It was found that Fomalhaut belongs to the class of young stars. This star is about 250 million years old. For comparison, our Sun is 4.57 billion years old. It turns out that our sun older than a star Fomalhaut 18 times!

According to the latest work of astronomers, it turned out that Fomalhaut is part of a wide triple star system. The main star Fomalhaut A was first identified to have an orange dwarf star, TW Southern Fish (Fomalhaut B), 0.9 light-years away. The third star in the system is the red dwarf LP 876-10 (Fomalhaut C). It is 2.5 light years away from Fomalhaut A and has its own comet belt.

The star Fomalhaut is one of the Castor group. This group includes stars that have a common relationship, as well as a common route of movement in space. In addition to the star Fomalhaut, this group also includes such famous celestial bodies as Vega, Alderamin, Castor, Alpha Libra and others.

9

• Alternative name:α Virgo
• Apparent magnitude: 1.04 (variable)
• Distance to the Sun: 250 St. years

The star Spica or Alpha Virgo is the brightest star in the constellation Virgo. With an apparent magnitude of 0.98, Spica is the 15th brightest star in the night sky. Its absolute magnitude is -3.2, and the distance to Earth is 262 light years.

Spica is a close binary star whose components complete one revolution around a common center of mass every four days. They are located close enough to each other that they cannot be seen in a telescope as two separate stars. Changes in the orbital motion of this pair result in a Doppler shift in the absorption lines of their respective spectra, making them a spectral binary pair. The orbital parameters for this system were first derived using spectroscopic measurements.

The main star has a spectral type B1 III-IV. It is a massive star with 10 times the mass of the Sun and seven times the radius. The total luminosity of this star is 12,100 times that of the Sun and eight times that of its companion. The primary star of this pair is one of the closest stars to the Sun that has enough mass to end its life in a Type II supernova explosion.

The secondary star of this system is one of the few stars in which the Struve-Sahade effect is observed. This is an anomalous change in the strength of the spectral lines during an orbit, where the lines become weaker as the star moves away from the observer. This star is smaller than the main one. Its mass is seven times that of the Sun, and the radius of the star is 3.6 times the radius of the Sun. The star has a spectral type of B2 V, making it a main sequence star.

8

• Alternative name:α Scorpio
• Apparent magnitude: 0.91 (variable)
• Distance to the Sun:~610 St. years

The brightest star in the constellation Scorpio and one of the brightest stars in the night sky, a red supergiant. It is part of Bubble I, an area adjacent to the Local Bubble, which includes the Solar System.

The word Antares comes from the Greek ανταρης, which means "against Ares (Mars)" due to the fact that it resembles the planet Mars with its red color. The color of this star has aroused the interest of many nations throughout history. In the Arabic astronomical tradition, it was called Kalb-al-Akrab (Heart of the Scorpion). Many ancient Egyptian temples are oriented in such a way that the light of Antares played a role in the ceremonies that took place in them. In ancient Persia, Antares, which they called Satevis, was one of the four royal stars. In ancient India it was called Jyestha.

Antares is a class M supergiant, with a diameter of approximately 2.1·10 9 km. Antares is about 600 light-years from Earth. Its luminosity in the visible wavelength range exceeds that of the sun by 10,000 times, but given the fact that the star radiates a significant part of its energy in the infrared, the total luminosity exceeds that of the sun by 65,000 times. The mass of the star is between 12 and 13 solar masses. The huge size and relatively small mass indicate that Antares has a very low density.

Along with Aldebaran, Spica and Regulus, Antares is one of the four brightest stars near the ecliptic. Being about 5 ° from the ecliptic, it is periodically covered by the Moon and occasionally by planets. The sun passes near Antares a little less than 5° north each year on December 2nd.

Antares has a hot blue companion star (Antares B) at a distance of about 2.9 arcseconds. Although it is 5th magnitude, it is usually difficult to see due to the brightness of Antares A. It can be observed with a small telescope for several seconds during occultation by the Moon, when the main component of Antares is obscured by the Moon; Antares B was discovered by the Viennese astronomer Johann Tobias Bürg during one of these occultations on April 13, 1819. The orbital period of the satellite is 878 years.

7

• Alternative name:α Southern Cross
• Apparent magnitude: 0,79
• Distance to the Sun:~330 St. years

The star Acrux or alpha of the Southern Cross is the "Polar Star" of the Southern Hemisphere. With its help, travelers still determine the direction to the south.

The star Acrux or Alpha Southern Cross is the brightest star in the constellation Southern Cross and the twelfth brightest star in the entire expanse of the night sky. This star is one of the few observable stars in the night sky that does not have a name. mythological origin. It was formed simply from the name of the constellation Southern Cross itself, which in Latin sounds like "Crux". Alpha constellation Southern Cross - Alpha Crux - A-Crux.

Observations made by astronomers in the past and present century have shown that Acrux is actually a system consisting of three stars. These stars can be distinguished from each other by observing them even with a home telescope. The first star of the Acrux system - Alpha-1 is a spectroscopic binary star. With her companion, she rotates in one orbit with a period of 76 Earth days.

As we have already found out, Acrux is a system of three stars, the nearest of which are at a distance of 320 astronomical units from the solar system. Alpha-1 - the main star of this system has a magnitude of 1.40. Its mass is approximately 14 times the mass of our Sun. The second largest star in this system, Alpha-2, has a magnitude of 2.04 and a mass 10 times the weight of the Sun. As for the third star, it is still not clear whether it is gravitationally bound to the Akrux system or not. According to some data, it is a subgiant included in this system. According to others, this is a separate spectroscopic binary star, which is not related to Acrux. Perhaps further research by astronomers will help resolve this issue.

6

• Alternative name:(β Centauri
• Apparent magnitude: 0.61 (variable)
• Distance to the Sun:~400 St. years

The second brightest star in the constellation Centaurus and the eleventh brightest star in the night sky. Hadar is a blue-white giant located about 525 light-years from the solar system.

Beta Centauri has the two most common names, Hadar and Agena. The first comes from the Arabic language and is translated as "bottom". The second has Latin roots and is translated as "knee". Both names are associated with the location of the star in the constellation Centaurus.

The data obtained by the astronomer J. Booth, back in 1935, confirmed that Beta Centauri is in fact a system consisting of three stars. The star Hadar itself, or, as it is also called, Hadar-A, is a pair of twin stars of spectral class B, which are three astronomical units apart from each other. This distance can vary due to the elliptical orbit in which these bodies move in outer space around a common center of mass. Hadar-B is a space object remote from the first two at a considerable distance - 210 astronomical units. This star is smaller.

All three stars of the Hadar system move in one orbit around a common center of mass with a period of 600 Earth years. Usually, when it comes to the Hadar system, astronomers have in mind the Hadar-A group of stars, consisting of twin stars. The twin stars of the Hadar system are ancient cosmic objects. The data obtained indicate that their age is at least 12 million years. Companion stars also have a fairly large mass. According to various sources, it is within 11-14 masses of our Sun. Current evidence indicates that the Hadar-A twin stars are constantly expanding. This leads some astronomers to believe that they will soon turn into red supergiants, and then explode like supernovae.

5

• Alternative name:α Eridani
• Apparent magnitude: 0,46
• Distance to the Sun: 69 St. years

Achernar is the brightest star in the constellation Eridani and the ninth brightest star in the entire night sky. It is located at the southern end of the constellation. Of the ten brightest stars, Achernar is the hottest and bluest. The star rotates unusually quickly around its axis, which is why it has a strong elongated shape. Achernar is a double star. As of 2003, Achernar is the least spherical star ever studied. The star rotates at a speed of 260-310 km/s, which is up to 85% of the break up velocity. Due to the high speed of rotation, Achernar is strongly flattened - its equatorial diameter is more than 50% larger than its polar diameter. Achernar's axis of rotation is tilted at an angle of about 65% to the line of sight.

Achernar is a bright blue binary star with a total mass of about eight solar masses. It is a main sequence star of spectral type B6 Vep, with a luminosity of more than three thousand times that of the Sun. The distance from the star to the solar system is approximately 139 light years.

Observations of the star with the VLT telescope showed that Achernar has a companion orbiting at a distance of about 12.3 AU. and rotating with a period of 14-15 years. Achernar B is a star with a mass of about two solar masses, spectral type A0V-A3V.

The name comes from the Arabic آخر النهر (ākhir an-nahr) - "end of the river" and most likely originally belonged to the star θ Eridani, which bears its own name Akamar with the same etymology.

4

• Alternative name:β Orionis
• Apparent magnitude: 0.12 (variable)
• Distance to the Sun:~870 St. years

With an apparent magnitude of 0.12, Rigel is the seventh brightest star in the sky. Its absolute magnitude is -7 and it is located at a distance of ~870 light-years from us.

Rigel has a spectral class of B8Iae, a surface temperature of 11,000 Kelvin, and its luminosity is 66,000 times greater than that of the Sun. The star has a mass of 17 solar masses and a diameter 78 times that of the Sun.

Rigel is the brightest star in our local region of the Milky Way. The star is so bright that when viewed from a distance of one astronomical unit (the distance from the Earth to the Sun), it will shine as an extremely bright ball with an angular diameter of 35 ° and an apparent magnitude of -32 (for comparison: the apparent magnitude is − 26.72). The power flow at this distance will be the same as from a welding arc from a distance of a few millimeters. Any object so close will be vaporized by the strong stellar wind.

Rigel is a famous binary star, which was first observed by Vasily Yakovlevich Struve in 1831. Although Rigel B has a relatively faint magnitude, its proximity to Rigel A, which is 500 times brighter, makes it one of the targets of amateur astronomers. According to calculations, Rigel B is removed from Rigel A at a distance of 2200 astronomical units. Due to such a colossal distance between them, there is no sign of orbital motion, although they have the same proper motion.

Rigel B itself is a spectroscopic binary consisting of two main-sequence stars orbiting a common center of gravity every 9.8 days. Both stars belong to the spectral class B9V.

Rigel is a variable star, which is not common in supergiants, with a magnitude range of 0.03-0.3, changing every 22-25 days.

3

• Alternative name:α Centauri
• Apparent magnitude: −0,27
• Distance to the Sun: 4.3 St. years

Alpha Centauri is a double star in the constellation Centaurus. Both components, α Centauri A and α Centauri B, are visible to the naked eye as a single star −0.27m, making α Centauri the third brightest star in the night sky. Most likely, this system also includes the red dwarf Proxima or α Centauri C, invisible to the naked eye, which is separated from the bright double star by 2.2°. All three are the closest stars to the Sun, with Proxima somewhat closer than the others at the moment.

α Centauri has its own names: Rigel Centaurus (romanization of Arabic رجل القنطور‎ - “foot of the Centaur”), Bungula (possibly from Latin ungula - “hoof”) and Toliman (possibly from Arabic الظلمان‎ [al-Zulman] "Ostrich"), but they are used quite rarely.

The first star, Centauri A, is very similar to the Sun. There is a cold thin layer in the atmosphere. The mass of Alpha is 0.08 more than the mass of the Sun, it shines brighter and hotter. She is often reproached that she obscures Beta Centauri, but thanks to the dual union, her girlfriends are visible in the sky.

The second star - Centauri B is 12% smaller than the Sun, therefore, colder. It is separated from Centaurus A by a distance of 23 astronomical units. The stars are highly interconnected. The forces of mutual attraction affect the processes occurring on the surfaces, as well as the formation of planets. Centauri B rotates relative to Centauri A. The orbit looks like a highly elongated ellipse. The turnover takes 80 years, which is very fast on a cosmic scale.

The third component of the system is the star Proxima Centauri. The name of the star means "nearest". It got its name because, thanks to its orbit, it approaches the Earth as close as possible. An object of the eleventh magnitude. Proxima revolves around two stars in 500 thousand years. According to some sources, the rotation period reaches a million years. Its temperature is very low in order to heat nearby objects, so the planets near it are not searched for. Proxima is a red dwarf that sometimes produces very powerful flares.

It takes 1.1 million years to get to Alpha Centauri by modern spacecraft, so it won't happen in the near future.

2

• Alternative name:α Carina
• Apparent magnitude: −0,72
• Distance to the Sun: 310 St. years

The star Canopus or Alpha Carina is the brightest star in the constellation Carina. With an apparent magnitude of -0.72, Canopus is the second brightest star in the sky. Its absolute magnitude is -5.53, and it is 310 light years away from us.

Canopus has a spectral class of A9II, a surface temperature of 7350° Kelvin, and a luminosity 13,600 times that of the Sun. The star Canopus has a mass of 8.5 solar masses and a diameter 65 times that of the Sun.

The diameter of the star Canopus is 0.6 AU, or 65 times that of the Sun. If Canopus were located at the center of the solar system, then its outer edges would extend three-quarters of the way to Mercury. The Earth had to be removed to a distance of three times the orbit of Pluto in order for Canopus to look in the sky just like our Sun.

Canopus is a supergiant of spectral type F and, when viewed with the naked eye, has White color. With a luminosity 13,600 times that of the Sun, Canopus is, in fact, the brightest star, up to 700 light-years from the solar system. If Canopus were located at a distance of 1 astronomical unit (the distance from the Earth to the Sun), then it would have an apparent magnitude of -37.

1

• Alternative name:α Canis Major
• Apparent magnitude: −1,46
• Distance to the Sun: 8.6 St. years

The brightest star in the night sky is undoubtedly Sirius. It shines in the constellation Canis Major and is highly visible in the Northern Hemisphere during the winter months. Although its luminosity exceeds the luminosity of the Sun by 22 times, it is by no means a record in the world of stars - the high visible brightness of Sirius is due to its relative proximity. In the Southern Hemisphere, it is visible during summer, north of the Arctic Circle. The star is located approximately 8.6 light years from the Sun and is one of the stars closest to us. Its brilliance is the result of its true brightness and its proximity to us.

Sirius has a spectral type of A1Vm, a surface temperature of 9940° Kelvin, and a luminosity 25 times that of the Sun. The mass of Sirius is 2.02 solar masses, the diameter is 1.7 times greater than that of the Sun.

Back in the 19th century, astronomers, when studying Sirius, drew attention to the fact that its trajectory, although it is a straight line, is subject to periodic fluctuations. In the projection of the starry sky, it (the trajectory) looked like a wavy curve. Moreover, its periodic fluctuations could be detected even in a short period of time, which in itself was already surprising since we were talking about stars - which are billions of kilometers away from us. Astronomers have suggested that a hidden object that revolves around Sirius with a period of about 50 years is to blame for such “wobbles”. 18 years after a bold assumption, near Sirius, it was possible to discover a small star, which has a magnitude of 8.4 and is the first discovered white dwarf, moreover, also the most massive one discovered to date.

The Sirius system is about 200-300 million years old. Initially, the system consisted of two bright bluish stars. The more massive Sirius B, consuming its resources, became a red giant, after which it ejected its outer layers and became a white dwarf about 120 million years ago. Sirius is known colloquially as the "Dog Star", reflecting his belonging to the constellation Canis Major. The sunrise of Sirius marked the flood of the Nile in Ancient Egypt. The name Sirius comes from the ancient Greek "luminous" or "hot".

Sirius is brighter than the nearest star to the Sun - Alpha Centauri, or even supergiants such as Canopus, Rigel, Betelgeuse. Knowing the exact coordinates of Sirius in the sky, it can be seen with the naked eye and during the day. For best viewing, the sky must be very clear and the Sun low on the horizon. Currently, Sirius is approaching the solar system at a speed of 7.6 km / s, so over time, the apparent brightness of the star will slowly increase.

Note:

1. (Alpha Canis Major; αCMa, Sirius). The brightest star in the constellation Canis Major and the brightest star in the sky. It is a visual binary star with an orbital period of 50 years, whose main component (A) is an A star, and the second component (B, Puppy) is an 8th magnitude white dwarf. Sirius B was first detected optically in 1862 and its type was determined from its spectrum in 1925. Sirius is 8.7 light-years away from us and ranks seventh in proximity to the solar system. The name is inherited from the ancient Greeks and means "scorching", which emphasizes the brilliance of the star. In connection with the name of the constellation to which Sirius belongs, it is also called the "Dog Star". The third star, a brown dwarf, is closer to (A) than component (B), discovered by French astronomers in 1995.
2. (Alpha Bootes, α Boo, Arcturus). The brightest star in the constellation Bootes, the orange giant, K-star, is the fourth brightest star in the sky. Double, variable. The name is of Greek origin and means "bear's keeper". Arcturus was the first star to be seen by day with a telescope by the French astronomer and astrologer Morin in 1635.
3. (Alpha Lyrae; α Lyr, Vega). The brightest star in the constellation Lyra and the fifth brightest star in the sky. This is an A-star. In 2005, the Spitzer Space Telescope took images of Vega, as well as the surrounding dust in the infrared spectrum. A planetary system is formed around the star.
4. (Alpha Aurigae; α Aur, Chapel). The brightest star in the constellation Auriga, a spectroscopic binary whose primary component is a giant G star. Her name is of Latin origin and means "little goat".
5. (Beta Orionis; β Ori, Rigel). The brightest star in the constellation Orion. The Greek letter Beta is used for its designation, although it is slightly brighter than Betelgeuse, designated Alpha Orionis. Rigel is a supergiant, B-star with a 7th magnitude companion. The name, which is of Arabic origin, means "giant's foot".
6. (Alpha Small Dog; αCMi, Procyon). The brightest star in the constellation Canis Minor. Procyon is the fifth brightest of all stars. In 1896, J. M. Scheberl discovered that Procyon is a binary system. The main companion is a normal F star and the weak companion is an 11th magnitude white dwarf. The circulation period of the system is 41 years. The name Procyon is of Greek origin and means "before the dog" (a reminder that the star rises before the "Dog Star", i.e. Sirius).
7. (Alpha Eagle; α Aql, Altair). The brightest star in the constellation Aquila. The Arabic word "altair" means "flying eagle". Altair - A-star. This is one of the closest among the brightest stars (located at a distance of 17 light years).
8. (Alpha Orion; α Ori, Betelgeuse). A red supergiant, an M star, is one of the largest known stars. Using point interferometry and other interference methods, it was possible to measure its diameter, which turned out to be approximately 1000 diameters of the Sun. The presence of large bright "star spots" was also detected. Ultraviolet observations made with the Hubble Space Telescope have shown that Betelgeuse is surrounded by a vast chromosphere, approximately twenty solar masses. Variable. The brightness varies irregularly between values ​​of 0.4 and 0.9 with a period of about five years. It is noteworthy that during the observation period from 1993 to 2009, the diameter of the star decreased by 15%, from 5.5 astronomical units to approximately 4.7, and astronomers cannot yet explain what this is connected with. At the same time, the brightness of the star did not change noticeably during this time.
9. (Alpha Taurus; α Tau, Aldebaran). The brightest star in the constellation Taurus. The Arabic name means “next” (i.e. following the Pleiades). Aldebaran is a giant K star. Variable. Although in the sky the star looks like part of the Hyades cluster, in fact it is not a member of it, being twice as close to Earth. In 1997, it was reported that it had a possible satellite - a large planet (or a small brown dwarf), with a mass equal to 11 Jupiter masses at a distance of 1.35 AU. Pioneer 10 unmanned spacecraft heading towards Aldebaran. If nothing happens to it along the way, it will reach the region of the star in about 2 million years.
10. (Alpha Scorpio; αSco, Antares). The brightest star in the constellation Scorpio. Red supergiant, M-star, variable, double The name is of Greek origin and means “competitor of Mars”, which is reminiscent of the wonderful color of this star. Antares is a semi-regular variable star whose brightness varies between magnitudes 0.9 and 1.1 over a period of five years. It has a blue companion star of 6th magnitude, only 3 arc seconds distant. Antares B was discovered during one of these occultations on April 13, 1819. The orbital period of the satellite is 878 years.
11. (Virgo Alpha; αVir, Spica). The brightest star in the constellation Virgo. This is an eclipsing binary, a variable whose brightness varies by about 0.1 magnitude with a period of 4.014 days. Main component - blue and white B-star with a mass of about eleven solar masses. The name means "corn cob".
12. (Beta Gemini; β Gem, Pollux). The brightest star in the constellation Gemini, although its designation is Beta, not Alpha. It seems unlikely that Pollux has become brighter since Bayer (1572-1625). Pollux is an orange giant, a K-star. In classical mythology, the twins Castor and Pollux were the sons of Leda. In 2006, an exoplanet was discovered around the star.
13. (Southern Pisces Alpha; α PsA,
14. (Epsilon Canis Major; ε CMa, Adara). The second brightest (after Sirius) star in the constellation Canis Major, a giant B-star. Has a 7.5 m companion star. The Arabic name for the star means "virgin". Approximately 4.7 million years ago, the distance from ε Canis Majoris to the Earth was 34 light years, and the star was the brightest in the sky, its brightness was −4.0 m
15. (Alpha Gemini; a Gem, Castor). The second brightest in the constellation of Gemini after Pollux. Its naked-eye magnitude is estimated at 1.6, but this is the combined brightness of a multiple system of at least six components. There are two A-stars of magnitudes 2.0 and 2.9, forming a close visual pair, each of which is a spectroscopic binary, and a more distant red star of 9th magnitude, which is an eclipsing binary.
16. (Gamma Orionis; γ Ori, Bellatrix). Giant, B-star, variable, double. The name is of Latin origin and means "warrior woman". One of the 57 navigational stars of antiquity
17. (Beta Taurus; β Tau, Nat). The second brightest in the constellation Taurus, lying on the tip of one of the bull's horns. The name comes from the Arabic expression "butting with horns". This star is old maps portrayed right leg human figure in the constellation Auriga and had another designation, Gamma Auriga. Elnat is a B-star.
18. (Epsilon Orionis; ε Ori, Alnilam). One of the three bright stars that make up Orion's belt. The Arabic name translates as "string of pearls". Alnilam - supergiant, B-star, variable
19. (Zeta Orionis; ζ Ori, Alnitak). One of the three bright stars that make up Orion's belt. The Arabic name translates as "belt". Alnitak is a supergiant, O-star, triple star.
20. (Epsilon Ursa Major; εUMa, Aliot). The brightest star in the constellation Ursa Major. The Greek letters in this case are assigned to the stars in the order of their position, not brightness. Alioth - A-star, possibly has a planet 15 times more massive than Jupiter.
21. (Alpha Ursa Major; αUMa, Dubhe). One of the two stars (the second - Merak) of the Big Dipper in Ursa Major, called Pointers. Giant, K-star, variable. The 5th magnitude companion revolves around it with a period of 44 years. Dubhe, literally "bear", is a shortened version of the Arabic name meaning "the back of a larger bear".
22. (Alpha Perseus;α Per, Mirfak). The brightest star in the constellation Perseus. Yellow supergiant, F-star, variable. The name, of Arabic origin, means "elbow".
23. (This Big Dipper; ηUMa, Benetnash). The star at the end of the tail. B-star, variable. The Arabic name means “leader of mourners” (for the Arabs, the constellation was seen as a hearse, not a bear).
24. (Beta Canis Major; βCM, Mirzam). The second brightest in the constellation Canis Major. The giant B-star, variable, is the prototype of a class of weakly variable stars like Beta Canis Majoris. Its brightness changes every six hours by several hundredths of a magnitude. Such a low level of variability is not detectable with the naked eye.
25. (Alpha Hydra; αHya, Alphard). The brightest star in the constellation Hydra. The name is of Arabic origin and means "secluded snake". Alphard - K-star, variable, triple.
26. (Alpha Ursa Minor; αUMi, Polar). The brightest star in the constellation Ursa Minor, located near the north celestial pole (at a distance of less than one degree). Polaris is the closest Delta Cephei pulsating variable star to Earth with a period of 3.97 days. But Polaris is a very non-standard Cepheid: its pulsations decay over a period of about tens of years: in 1900, the change in brightness was ± 8%, and in 2005 - approximately 2%. In addition, during this time, the star became on average 15% brighter.