The dimmest star in the sky. The brightest stars

>The brightest star

Sirius is the brightest star in the modern Universe: history of bright stars in the past, Arcturus, Vega, Rigel, Deneb, influence of the movement of the Solar system in the galaxy.

For all residents below 83 degrees north latitude the brightest star The visible Universe is Sirius. It reaches 1st magnitude and is the fifth brightest celestial object. But was he always the brightest star?

The brightest star in the modern Universe

Of course, in first place in terms of brightness is . The star is 8.6 light years away and played a vital role for the ancient Egyptians, who based their calendar on it.

Interesting: The brightest star north of the celestial equator is , whose magnitude reaches -0.04.

Now keep this in mind, since it was she who got the title of the brightest star in the sky 200,000 years ago.

Where do such changes in the brightness rating of stellar celestial bodies come from? It's all about constant movement. Our solar system travels at a speed of 250 km/s. A full passage takes 250 million years. It turns out that in 4.5 billion years of existence we have completed only 18 orbital galactic flybys.

In addition, the Solar System also oscillates relative to the galactic plane (up and down). This takes another 93 million years. The stars move at the same time as us. In the video you can follow the movement of stars in the constellation Ursa Major.

Movement of the Big Dipper

All these movements are carried out quite chaotically and take long periods of time. Modern Sirius and Alpha Centauri are considered “the brightest stars in the Universe” because they are close. But there are also those who are distant, but still act as the brightest representatives.

Such differences are called apparent magnitude. She is connected with the earthly observer. Therefore, scientists turn to a more accurate indicator - the absolute value (brightness at a distance of 10 parsecs). Send Deneb this distance and its magnitude becomes -8.4. Study the list of the brightest stars in the sky from the perspective of an earthly observer.

List of the brightest stars in the Universe visible from Earth

№	Name	Distance, St. years	Apparent value	Absolute value	Spectral class	Celestial hemisphere
0		0,0000158	−26,72	4,8	G2V
1		8,6	−1,46	1,4	A1Vm	South
2		310	−0,72	−5,53	A9II	South
3	Toliman (α Centauri)	4,3	−0,27	4,06	G2V+K1V	South
4		34	−0,04	−0,3	K1.5IIIp	Northern
5		25	0.03 (variable)	0,6	A0Va	Northern
6		41	0,08	−0,5	G6III + G2III	Northern
7		~870	0.12 (variable)	−7	B8Iae	South
8		11,4	0,38	2,6	F5IV-V	Northern
9	Achernar (α Eridani)	69	0,46	−1,3	B3Vnp	South
10		~530	0.50 (variable)	−5,14	M2Iab	Northern
11	Hadar (β Centauri)	~400	0.61 (variable)	−4,4	B1III	South
12		16	0,77	2,3	A7Vn	Northern
13	Acrux (α Southern Cross)	~330	0,79	−4,6	B0.5Iv + B1Vn	South
14		60	0.85 (variable)	−0,3	K5III	Northern
15		~610	0.96 (variable)	−5,2	M1.5Iab	South
16		250	0.98 (variable)	−3,2	B1V	South
17		40	1,14	0,7	K0IIIb	Northern
18		22	1,16	2,0	A3Va	South
19	Mimosa (β Southern Cross)	~290	1.25 (variable)	−4,7	B0.5III	South
20		~1550	1,25	−7,2	A2Ia	Northern
21		69	1,35	−0,3	B7Vn	Northern
22		~400	1,50	−4,8	B2II	South
23		49	1,57	0,5	A1V + A2V	Northern
24	Hacrux (γ Southern Cross)	120	1.63 (variable)	−1,2	M3.5III	South
25	Shaula (λ Scorpio)	330	1.63 (variable)	−3,5	B1.5IV	South

By human standards of life, all stars and constellations look the same. It’s just that they don’t have time to change over a period of 80-100 years. But if you lived for centuries, you would notice how they slowly shift - the correct movement. For example, Barnard's Star and 61 Cygni move at 10 and 3.2 arcseconds per year. But proper motion measures speed relative to our line of sight.

The brightest star in the Universe in the past

Radial movement reveals the secrets of leadership in past centuries. Light disappears with the inverse square of the distance. Take a burning candle and move it further. The light will remain the same, but it will not seem as bright to you.

We are now moving towards the solar apex point near the star Omicron Hercules at a speed of 16.5 km/s. But you can rewind the path back. For example, a Delta Scuti magnitude of 2.4 would increase to -1.8, exceeding the brightness of modern Sirius. And 4.7 million years BC. the star Hadara reached magnitude -4 instead of the modern 1.5.

Arcturus is currently diving through our galactic neighborhood at a rate of 2 arcseconds per year. It is very close to its maximum brightness (a process that takes 4,000 years) and will gradually begin to fade from view.

The brightest star in the Universe in the future

Get ready for the star Albireo to close its distance by 300 light years and reach a magnitude of -0.5. Future scientists will finally be able to find out whether it is a double pair or not.

Not only astronomers and romantics love to look at the sky. We all look up to the stars from time to time and admire their eternal beauty. That is why each of us is at least sometimes interested in which star in the sky is the brightest.

The Greek scientist Hipparchus first asked this question, and he proposed his classification 22 centuries ago! He divided the stars into six groups, where the first magnitude stars were the brightest he could observe, and the sixth magnitude were those barely visible to the naked eye.

Needless to say that we are talking about relative brightness, and not about the actual ability to glow? Indeed, in addition to the amount of light produced, the brightness of a star observed from Earth is affected by the distance from this star to the observation site. It seems to us that the brightest star in the sky is the Sun, because it is closest to us. In fact, it is not at all a bright and very small star.

Nowadays, approximately the same system for distinguishing stars by brightness is used, only improved. Vega was taken as the reference point, and the brightness of the remaining stars is measured from its indicator. The brightest stars have a negative index.

So, we will consider exactly those stars that are recognized as the brightest according to the improved Hipparchus scale

10 Betelgeuse (α Orionis)

The red giant, with 17 times the mass of our Sun, rounds out the top 10 brightest night stars.

This is one of the most mysterious stars in the Universe, because it is capable of changing its size, while its density remains unchanged. The color and brightness of the giant varies at different points.

Scientists expect Betelgeuse to explode in the future, but given that the star is located at a huge distance from the Earth (according to some scientists - 500, according to others - 640 light years), this should not affect us. However, for several months the star can be seen in the sky even during the day.

9 Achernar (α Eridani)

A favorite of science fiction writers, a blue star with a mass 8 times greater than that of the Sun looks very impressive and unusual. The star Achernar is flattened so that it resembles a rugby ball or a tasty torpedo melon, and the reason for this is a fantastic rotation speed of more than 300 km per second, approaching the so-called separation speed, at which the centrifugal force becomes identical to the force of gravity.

8 Procyon (α Canis Minor)

One of the two “dog stars” is similar to Sirius in that it is the brightest star in the constellation Canis Minor (and Sirius is the brightest star in Canis Major), and in that it is also double.

Procyon A is a pale yellow star about the size of the Sun. It is gradually expanding, and in 10 million years it will become an orange or red giant. According to scientists, the process is already underway, as evidenced by the unprecedented brightness of the star - it is more than 7 times brighter than the sun, although similar in size and spectrum.

Procyon B, its companion, a dim white dwarf, is about the same distance from Procyon A as Uranus is from the Sun.

And there were some mysteries here. Ten years ago, a long-term study of the star was undertaken using an orbiting telescope. Astronomers were eager to get confirmation of their hypotheses. However, the hypotheses were not confirmed, and now scientists are trying to explain what is happening on Procyon in some other way.

Continuing the “dog” theme – the name of the star means “in front of the dog”; this means that Procyon appears in the sky before Sirius.

7 Rigel (β Orionis)

In seventh place in terms of relative (observed by us) brightness is one of the most powerful stars in the Universe with an absolute magnitude of -7, that is, the brightest of the stars located more or less nearby.

It is located 870 light years away, so less bright but closer stars appear brighter to us. Meanwhile, Rigel is 130 thousand times brighter than the Sun and 74 times larger in diameter!

The temperature on Rigel is so high that if something were to be at the same distance from it as the Earth is relative to the Sun, this object would immediately turn into a stellar wind!

Rigel has two companion stars, almost invisible in the bright glow of the blue-white supergiant.

6 Chapel (α Auriga)

Capella ranks third among the brightest stars in the Northern Hemisphere. Of the stars of the first magnitude (the famous Polaris is only of the second magnitude), Capella is located closest to the North Pole.

This is also a double star, and the weaker of the pair is already becoming red, and the brighter is still white, although the hydrogen in its body has obviously already turned into helium, but has not yet ignited.

The name of the star means Goat, because the Greeks identified it with the goat Amalthea, who suckled Zeus.

5 Vega (α Lyrae)

The brightest of the Sun's neighbors can be observed throughout the entire Northern Hemisphere and almost the entire Southern Hemisphere, except Antarctica.

Vega is beloved by astronomers for being the second most studied star after the Sun. Although there is still a lot of mystery in this “most studied” star. What can we do, the stars are in no hurry to reveal their secrets to us!

Vega's rotation speed is very high (it rotates 137 times faster than the Sun, almost as fast as Achernar), so the star's temperature (and therefore its color) differs at the equator and at the poles. Now we see Vega from the pole, so it appears pale blue to us.

Around Vega there is a large cloud of dust, the origin of which is controversial among scientists. The question of whether Vega has a planetary system is also debatable.

4 The brightest star in the Northern Hemisphere is Arcturus (α Bootes)

In fourth place is the brightest star of the Northern Hemisphere - Arcturus, which in Russia can be observed anywhere throughout the year. However, it is also visible in the Southern Hemisphere.

Arcturus is many times brighter than the Sun: if we take into account only the range perceived by the human eye, then more than a hundred times, but if we take the intensity of the glow as a whole, then 180 times! This is an orange giant with an atypical spectrum. Someday our Sun will reach the same stage that Arcturus is at now.

According to one version, Arcturus and its neighboring stars (the so-called Arcturus Stream) were once captured by the Milky Way. That is, all these stars are of extragalactic origin.

3 Toliman (α Centauri)

This is a double, or rather, even a triple star, but we see two of them as one, and the third, dimmer one, which is called Proxima, as if separately. However, in fact, all these stars are not very bright, but are located not far from us.

Since Toliman is somewhat similar to the Sun, astronomers have long and persistently been looking for a planet near it, similar to Earth and located at a distance that makes life on it possible. In addition, this system, as already mentioned, is located relatively close, so the first interstellar flight will probably be there.

Therefore, the love of science fiction writers for Alpha Centauri is understandable. Stanislav Lem (creator of the famous Solaris), Asimov, Heinlein devoted pages of their books to this system; The action of the acclaimed film “Avatar” also takes place in the Alpha Centauri system.

2 Canopus (α Carinae) is the brightest star in the Southern Hemisphere

In absolute terms of luminosity, Canopus is much brighter than Sirius, which, in turn, is much closer to Earth, so that objectively it is the brightest night star, but from a distance (it is located at a distance of 310 light years) it seems dimmer to us than Sirius.

Canopus is a yellowish supergiant whose mass is 9 times the mass of the Sun, and it glows 14 thousand times more intensely!

Unfortunately, it is impossible to see this star in Russia: it is not visible north of Athens.

But in the Southern Hemisphere, Canopus was used to determine their location in navigation. In the same capacity, Alpha Carinae is used by our astronauts.

1 The brightest star in our starry sky is Sirius (α Canis Majoris)

The famous “dog star” (it was not for nothing that J. Rowling called her hero, who turned into a dog, that way), the appearance of which in the sky meant the beginning of vacation for ancient schoolchildren (this word means “dog days”) is one of the closest to the solar system and therefore perfectly visible from almost anywhere on Earth, except the Far North.

It is now believed that Sirius is a double star. Sirius A is twice as large as the Sun, and Sirius B is smaller. Although millions of years ago, apparently, it was the other way around.

Many peoples have left various legends associated with this star. The Egyptians considered Sirius to be the star of Isis, the Greeks - the dog of Orion taken to heaven, the Romans called him Canicula (“little dog”), in Old Russian this star was called Psitsa.

The ancients described Sirius as a red star, while we observe a bluish glow. Scientists can only explain this by assuming that all ancient descriptions were compiled by people who saw Sirius low above the horizon, when its color was distorted by water vapor.

Be that as it may, now Sirius is the brightest star in our sky, which can be seen with the naked eye even during the day!

It is pleasant to look at the sky not only for complete romantics and meticulous scientists. Every person from time to time loves to observe one of the most beautiful phenomena of our universe - bright stars. And therefore, it will be interesting for everyone to find out which luminaries are distinguished by the greatest radiance.

Sirius

Without a doubt, the brightest star in the night sky is Sirius. She ranks first in terms of her radiance. It is located in the constellation Canis Major and is clearly visible in the Northern Hemisphere in winter. Residents of the Southern Hemisphere can see it in the summer months, north of the Arctic Circle. Sirius is located approximately 8.6 light years from the Sun and is one of the brightest stars closest to us.

The brilliance of Sirius is a consequence of the proximity of the star to the solar system. It is one of the favorite objects for observation among amateur astronomers. Sirius is equal to 1.46 m.

Sirius is the brightest northern star. Astronomers back in the 19th century noticed that its trajectory, although straight, was still subject to periodic fluctuations. Astronomers began to guess that a hidden star revolving around Sirius with a period of about 50 years was responsible for these trajectory deviations. 18 years after this bold assumption, a small star measuring 8.4 m, belonging to the category of white dwarfs, was found near Sirius.

Canopus

For the first time, the ancient Greek scientist Hipparchus began to think about what the brightest star in the sky was. Its classification was proposed 22 centuries ago. Hipparchus was the first to divide the luminaries according to their brilliance into 6 magnitudes. The two brightest - Sirius and Canopus - are minus first magnitude. Canopus ranks second in brightness after Sirius, but is much less known. Apparently, for the reason that it is best observed from the Southern Hemisphere. From the northern territories, Canopus is observed only in subtropical latitudes.

For example, in Europe it is visible only from the south of Greece, and in the countries of the former USSR only residents of Turkmenistan can admire it. Astronomers in Australia and New Zealand were the luckiest in this regard. Here Canopus can be observed throughout the year.

According to scientists, the luminosity of Canopus is 15,000 times higher than the sun, which is a huge indicator. This luminary played a big role in navigation.

Currently, Canopus is a white supergiant located at a considerable distance from Earth - about 310 light years, or 2.96 quadrillion kilometers.

Vega

Looking at the sky on warm summer evenings, you can see a bright bluish-white dot. This is Vega - one of the most visible only in the Northern Hemisphere.

Vega is not only the main one in the constellation Lyra. She is the main luminary throughout the summer months. It is very convenient to observe from the Northern Hemisphere due to its location. From the end of spring until mid-autumn, it is the most noticeable luminary.

As with many other stars, many ancient legends are associated with Vega. For example, in the Far East there is a legend that Vega is a princess who fell in love with a simple man (represented in the sky by the star Altair). The girl's father, having learned about this, became angry, forbidding her to see an ordinary mortal. And in fact, Vega is separated from Altair by the foggy Milky Way. Only once a year, according to legend, thousands of forty form a sky bridge with their wings, and lovers have the opportunity to reunite. Later, the princess's tears fall to the ground - this is how the legend explains the meteor shower from the Perseid shower.

Vega is 2 times heavier than the Sun. The luminosity of the star is 37 times greater than that of the sun. Vega has such a huge mass that it will exist in its current state as a white star for another 1 billion years.

Arcturus

It is one of the brightest stars that can be observed from almost anywhere on Earth. In intensity it is second only to Sirius, Canopus, and the double star Alpha Centauri. The star is 110 times brighter than the Sun. Located in

An unusual legend

Arcturus owes its name to the constellation Ursa Major. Translated from ancient Greek, the word “arcturus” means “guardian of the bear.” According to the myth, Zeus placed him in place so that he would guard the nymph Callisto, who was transformed by the goddess Hera into a bear. In Arabic, Arcturus is called differently - “Haris-as-sama”, which means “guardian of the heavens”.

In northern latitudes the star can be observed all year round.

Alpha Centauri

Another one of the brightest stars, known to astronomers since ancient times, is Alpha Centauri. It is part of However, in reality it is not one star - it includes three components: the luminary Centauri A (also known as Toliman), Centauri B and the red dwarf Proxima Centauri.

In terms of age, Alpha Centauri is 2 billion years older than our solar system - this group was about 6 billion years old, while the Sun is only 4.5. The characteristics of these luminaries are as close as possible.

If you look at Alpha Centauri without special equipment, it is impossible to distinguish star A from B - it is thanks to this union that the impressive radiance of the star is achieved. However, once you equip yourself with an ordinary telescope, the small distance between the two celestial bodies becomes noticeable. The light emitted by the stars reaches our planet in 4.3 years. A modern spacecraft can reach Alpha Centauri in 1.1 million years, so this is unlikely to be possible in the near future. In summer, the star can be seen in Florida, Texas, and Mexico.

Betelgeuse

This star belongs to the category of red supergiants. The mass of Betelgeuse, or Alpha Orionis, is about 13-17 solar masses, and its radius is 1200 times the solar mass.

Betelgeuse is one of the brightest stars in the night sky. It is 530 light years away from Earth. Its luminosity is 140,000 times higher than that of the Sun.

This red supergiant is one of the largest and brightest stars today. If Betelgeuse were in the central part of the solar system, its surface would absorb several planets - Mercury, Venus, Earth and Mars. It is assumed that Betelgeuse is only about 10 million years old. Now the star is at a late stage of its evolution, and scientists assume that in the next few million years it will explode and turn into a supernova.

Procyon

The star Procyon is one of the brightest stars. He is the alpha of Canis Minor. In reality, Procyon consists of two luminaries - the second is called Gomeiza. Both of them can be observed without additional optics. The origin of the name “Procyon” is also very interesting. It was based on long-term observation of the starry sky. This word is literally translated as “before the Dog,” and a more literary translation sounds like “the harbinger of the dog.” The Arab peoples called Procyon “Sirius, shedding tears.” All these names have a direct connection with Sirius, who was worshiped by many ancient peoples. It is not surprising that over time, astrologers and priests discovered a harbinger of Sirius appearing in the sky - Procyon. He appears in the sky 40 minutes earlier, as if he were running ahead. If you depict the constellation Canis Minor in the picture, it turns out that Procyon is in its hind legs.

The star is located very close to the Earth - of course, this distance can only be called small by cosmic standards. It is separated from us by 11.41 light years. It moves towards the solar system at a tremendous speed of 4500 m per second. Procyon shines like 8 of our Suns, and its radius is no less than 1.9 times the radius of our star.

Astronomers classify it as a subgiant star. Based on the brightness of the glow, scientists concluded that the nuclear reaction between hydrogen and helium in its depths no longer occurs. Scientists are convinced that the process of star expansion has already begun. After a very long time, Procyon will turn into a red giant.

Polaris is the brightest star in Ursa Ursa.

This light was very unusual. First of all, it is worth noting the fact that it is closest to the planet’s north pole. And due to the daily rotation of the Earth, the stars move as if around the North Star. For this reason, it is often called Northern. As for the South Pole, there are no similar luminaries near it. In ancient times, the axis of the planet was directed to another sphere of the sky, and Vega took the place of the Northern Star.

Those who are interested in what is the brightest star in the sky, observed from the Northern Hemisphere, should know: Polaris cannot be called such. However, it is easy to find if you extend the line connecting the two luminaries of the Ursa Major bucket. Polaris is the very last star in the handle of the bucket of this constellation's neighbor, Ursa Minor. The brightest star in this cluster is also this luminary.

The Big Dipper is also of interest to astronomers. It is easy to see thanks to the shape of the bucket, which is clearly visible in the sky. The brightest star in the constellation is Alioth. In reference books it is designated by the letter epsilon, and it ranks 31st in brightness among all visible bodies.

Nowadays, as in the days of ancient astronomers, an ordinary person can observe the stars from the surface of the earth. However, it is quite possible that our great-grandchildren will be able to go to the brightest luminaries and learn much more interesting and entertaining information about them.

Astronomy

Translation

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

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

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

But those of us who don't get to witness such a spectacle on a periodic basis are missing the fact that stars seen from urban areas with high light pollution look different than when viewed in dark conditions. Their color and relative brightness immediately set them apart from their neighboring stars, and each has its own story.

People in the northern hemisphere can probably immediately recognize Ursa Major 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 next to the Southern Cross

Each star has its own life cycle to which it is tied from the moment of birth. When any star forms, the dominant element will be hydrogen - the most abundant element in the Universe - and its fate is determined only by its mass. Stars with 8% the mass of the Sun can ignite nuclear fusion reactions in their cores, 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 ones are destined to burn for trillions of years.

But the more mass a star gains, the hotter its core, and the larger the region in which nuclear fusion occurs. By the time it reaches solar mass, the star falls into class G, and its lifetime does not exceed ten billion years. Double the solar mass and you get a class A star that is bright blue and lives for less than two billion years. And the most massive stars, classes O and B, live only a few million years, after which their core runs out of hydrogen fuel. Not surprisingly, the most massive and hot stars are also the brightest. A typical class A star can be 20 times brighter than the Sun, and the most massive ones can be tens of thousands of times brighter!

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

And from that moment on, the star begins to burn heavier elements, expanding into a giant star, cooler, 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 greater distances than the original star was visible from.

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

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

9. Betelgeuse. A red giant star in the constellation Orion, Betelgeuse was a bright and hot O-class star until it ran out of hydrogen and switched to helium. Despite its low temperature of 3,500 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. Over 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 those we have considered. Procyon is a modest F-class star, just 40% larger than the Sun, and on the verge of running out of hydrogen in its core - meaning 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 may be brighter than all but seven 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 is 860 light years away, and with a temperature of just 12,000 degrees, Rigel is not a main sequence star - it is 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 it is actually two red giants with temperatures comparable to the Sun, but each is about 78 times brighter than the Sun. At a distance of 42 light years, it is the combination of its own brightness, relatively short 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 the aliens from the film “Contact”. Astronomers used it as a standard "zero magnitude" star. It is located only 25 light years away, belongs to the stars of the main sequence, and is one of the brightest class A stars known to us, and is also quite young, only 400-500 million years old. Moreover, 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. It is the brightest star in the northern hemisphere and can be easily found by the "handle" of the Big Dipper. It is 170 times brighter than the Sun, and following its 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 is itself fainter than any star in the ten. 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 number 2 on the list.

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. After all, 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 flickers frequently because its bright light can penetrate the lower atmosphere better than that of other stars. It's only 8.6 light-years away, but it's a class A star, twice as massive and 25 times brighter than the Sun.

It may surprise you that the top stars on the list are not the brightest or the closest stars, but rather combinations of bright enough and close enough to shine the brightest. Stars located twice as far away have four times less brightness, so Sirius shines brighter than Canopus, which shines brighter than Alpha Centauri, etc. 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 we can take away from this lesson: sometimes the things that seem most striking and most obvious to us turn out to be the most unusual. Common things can be much harder to find, but that means we need to improve our observation methods!

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. Although this work has not survived to this day, it is assumed that Hipparchus's list included about 850 stars (Subsequently, in the second century AD, Hipparchus's catalog was expanded to 1022 stars thanks to the efforts of another Greek astronomer, Ptolemy. Hipparchus included in his list of stars that could be distinguished in each constellation known at that time, he carefully described the location of each celestial body, and also sorted them on a brightness scale - from 1 to 6, where 1 meant the maximum possible brightness (or “stellar 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 only distinguish 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 capable of distinguishing objects of magnitude up to 31m.

Apparent magnitude - what is it?

With the advent of more precise light-measuring instruments, astronomers have decided to use decimals to denote magnitudes—for example, 2.75m—rather than simply roughly indicating the magnitude as 2 or 3.
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 shining 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.

Typically, 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 as seen from Earth, without taking into account the presence of an atmosphere that affects the view.

Absolute 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 distance 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 candle flame remained the same all the time.

Based on this fact, astronomers have found a new way to measure the brightness of a star, which was 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.

The absolute magnitude is usually indicated with a capital letter M, for example 2.75M. This method measures the star's actual luminosity, without corrections for distance or other factors (such as gas clouds, 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 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 summer began - the “dog days” season.

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

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

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

In 1844, German astronomer Friedrich Besse noticed a 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, and 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 consumed. Astronomers have calculated that Sirius's companion - named Sirius B - has the mass of our Sun packed into the size of our Earth.

Sixteen milliliters of the substance Sirius B (B is the 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 best time to observe Sirius is winter (for observers in 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 belt stars. Draw a line from the leftmost star of Orion's belt with an inclination of 20 degrees in the direction of the southeast. You can use your own fist as an assistant, which at arm's length covers about 10 degrees of the sky, so you will need about two times the width of your fist.

2. Canopus / Canopus

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

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

Canopus contains truly incredible power. It is not as close to us as Sirius, but it is 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! Moreover, Canopus is located 316 light years from the Sun, which is 37 times further than the brightest star in our night sky, Sirius.

Canopus is a yellow-white class F super giant star - a star with a temperature between 5500 and 7800 degrees Celsius. It has already exhausted all its hydrogen reserves, and is now processing its helium core into carbon. This helped the star “grow”: Canopus is 65 times larger than the Sun. If we replaced the Sun with Canopus, this yellow-white giant would devour 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 carbon-oxygen cores are most common, Canopus is so massive that it can begin to process its carbon into neon and oxygen as it morphs 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 approximately 40 degrees north of the brightest star in our night sky.

3. Alpha Centauri / Alpha Centauri

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

The Alpha Centauri system is interesting to us primarily for its proximity: located 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 Centauri A can even be called a twin star (both luminaries belong to the yellow G-class stars). In terms of luminosity, Centauri A is 1.5 times greater than the luminosity of the Sun, while its apparent magnitude is 0.01m. As for Centaurus B, its luminosity is half that of its brighter companion, Centaurus A, and its apparent magnitude is 1.3m. The luminosity of the red dwarf, Centauri 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 starry sky at a magnitude of -0.27m. True, it is best to observe this unusual three-star system 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 brightest stars of the Alpha Centauri system.

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

4. Arcturus / Arcturus

The first three stars of our ranking are mainly 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 is brighter than the brightest star of the Alpha Centauri system, Centauri A (-0.05m versus -0.01m).

Arcturus, also known as the “Guardian of the Ursa,” is an integral satellite of the constellation Ursa Major, and is very clearly visible in the northern hemisphere of the Earth (in Russia it is visible almost everywhere). The name Arcturus comes 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 luminosity of the “Ursa Guardian” is 215 times greater than our daylight star. 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 “Ursa Guard” is -0.04m.

It is noteworthy that Arcturus is in the final stages of his stellar life. Due to the constant struggle between gravity and pressure from the star, the Guardian Dipper is now 25 times the diameter of our Sun.

Ultimately, the outer layer of Arcturus will disintegrate and transform into the form of a planetary nebula, similar to the well-known Ring Nebula (M57) in the constellation Lyra. After this, 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. To do this, after you find Arcturus, you simply need to continue the Big Dipper arc further.

How to find Arcturus: Arcturus is the alpha (i.e. the brightest star) of the spring constellation Bootes. To find the “Ursa Guardian,” you just need to first find the Big Dipper (Ursa Major) and mentally continue the arc of its handle until you come across a bright orange star. This will be Arcturus, a star that forms, within 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 Lyra constellation, which is also home to the equally famous Ring Nebula (M57) and the star Epsilon Lyrae.

Ring Nebula (M57)

The Ring Nebula is a glowing 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 it 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 called a “double double” star.

Vega is a hydrogen-burning dwarf star, 54 times brighter than our Sun, while its mass is only 1.5 times greater. 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 Earth). By the standards of the Solar System, the outskirts of such a disk would end approximately at the boundaries of the Kuiper Belt. This is a very important discovery, because it is believed that a similar disk was 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 discovered “holes” in the disk of gas surrounding Vega, which could reasonably indicate that planets have already formed around this star. This discovery attracted 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 such contacts have never been recorded in real life.

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, and an astronomer from Harvard University acted as a photographer. Note that stars dimmer than the 2nd apparent magnitude were generally not accessible 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 will not be difficult. The easiest way to find Vega is to initially search for the Summer Triangle asterism. 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 is formed by Vega, the upper left by Deneb, and Altair shines below.

6. Capella / Capella

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

Today 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 red dwarf stars. The brighter of the two, the yellow giant, named Aa, is 80 times brighter and almost three times more massive than our star. The fainter 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, they will be 130 times more powerful than our Sun.

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

The Capella system is located 42 light years away from us, and its apparent magnitude is 0.08m.

If you are at 44 degrees north latitude (Pyatigorsk, Russia) or even further north, you will be able to observe Capella throughout the night: at these latitudes it never goes beyond the horizon.

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

How to find Capella: 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 Orion constellation, the inimitable star Rigel shines royally. 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 whose luminous power is 40 thousand times greater 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 well-recognized constellations (more popular than the Big Dipper constellation), since Orion is very easily identified 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 on the edges depict his arms and legs.

If you observe Rigel through a telescope, you can notice its second companion star, whose apparent magnitude is only 7m.

The mass of Rigel is 17 times greater than 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 incredible light from its explosion. However, it could also happen that Rigel could 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 continue to be born here.

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

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 one, 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 the harbinger of the appearance of Sirius, which is also called the “Dog Star”.

Procyon is a yellow-white star, luminosity 7 times greater than the Sun, while in dimensions it is only twice as large as our star. As with Alpha Centauri, Procyon shines so brightly in our night sky due to its proximity to the Sun - 11.4 light years separate our star from the distant star.

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

It is worth noting that Procyon, together with Betelgeuse and Sirius, forms a 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, speculation about the existence of a companion in Procyon was put forward back in 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 fainter companion, called Procyon B, is three times the size of Earth and has 60% the mass of the Sun. The brighter star of 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 western 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 southernmost point of the constellation named after 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: it is approximately 3,150 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 with its extreme point, the star Achernar

Achernar is quite close in apparent magnitude to the star Betelgeuse (number 10 in our ranking). However, Achernar is usually placed in 9th place in rankings of the brightest stars, since Betelgeuse is a variable star, whose apparent magnitude can fall from 0.5m to 1.2m, as it did in 1927 and 1941.

Achernar is a massive class B star, weighing eight times more than our Sun. It is now 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: Unfortunately, this star is not visible on Russian territory. In general, to view Achernar comfortably, you need to be south of 25 degrees 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

Don't think that Betelgeuse's importance is as low as its position in our ranking. The distance of 430 light years hides from us the true scale of the supergiant 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 means "hunter's armpit" in Arabic.

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

If Betelgeuse replaced the Sun in the solar system

The star Betelgeuse is a red supergiant of the M1 class, its diameter is 650 times greater than the diameter of our Sun, while its mass 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!

Once you begin observing Betelgeuse, you will see the star at the end of its long life. Its enormous mass suggests that it most likely converts all its elements into iron. If this is so, then in the near future (by cosmic standards) Betelgeuse will explode and turn into a supernova, and the explosion will be so bright that the power of the glow can be compared with the glow of the crescent moon visible from Earth. The birth of a supernova will leave behind a dense neutron star. Another theory suggests that Betelgeuse could evolve into a rare type of neon-oxygen dwarf star.

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