Betelgeuse in the night sky. Light of Orion

Light of Orion. A second sun may appear in the sky.

According to sources at the Mauna Kea observatory in Hawaii, the red giant Betelgeuse, located in the constellation of Orion, is rapidly changing its shape.
Only in the last 16 years the star has ceased to be round, it has shrunk at the poles. Such symptoms may indicate that in the very near future (we are talking about months, perhaps even weeks), the star will turn into a supernova.
Earthlings will be able to observe this event with the naked eye. Very bright in the sky bright Star. Scientists differ in their estimates of the degree of brightness, some say that it will be equal to the Moon, others promise the appearance of a second Sun.
The whole transformation will take about six weeks. In some parts of the Earth they will learn what white nights are, the rest of the unusual phenomenon will add two to three hours of daylight hours.
Then, the star will finally cool down and will be visible to earthlings in the form of a nebula.
For people, such events in space are not dangerous.
Waves of charged particles - a consequence of the explosion, of course, will reach our planet, but this will happen in a few centuries. Our distant descendants will receive a small dose of ionizing radiation.
The last time such an event was available to the eyes of earthlings was in 1054.

Betelgeuse (alpha).

largest visible star
On the right shoulder of Orion, in the crown of the Winter Hexagon, the beautiful Betelgeuse shines in the winter skies.

Constellation of Orion. Betelgeuse is a reddish-orange star in the upper left corner of the constellation.

This star is called alpha Orion for a reason, although the dazzling bluish Rigel - in the photo in the lower right corner - is brighter most of the time. Betelgeuse is in many ways a unique star that astronomers have been exploring for many years and discovering more and more. Interesting Facts.
First, Betelgeuse is one of the most big stars in the Universe. Its diameter is more than the diameter of the Sun by about a thousand times. Even the largest known star, VY Big Dog, surpasses Betelgeuse in diameter by only two times (and, accordingly, eight times in volume). So it is not in vain that this star bears the proud title of a red supergiant.
If it were in place of the Sun, it would almost fill the orbit of Saturn:

Only eight known stars (all red hypergiants) surpass Betelgeuse in volume, but they all look very dim in the earth's sky. The reason is simple: Betelgeuse is much closer than all of them.

Betelgeuse is 640 light-years away, which is very short on the scale of the Galaxy. Betelgeuse is the closest supergiant to us.
An interesting conclusion follows from this: Betelgeuse in the earth's sky has the largest apparent diameter of all stars (after the Sun, of course.)
It is clear that everything that is less than an arc minute in diameter is perceived by the human eye as a point. The angular diameters of absolutely all stars (except the Sun) are less than an arc minute, so they all look like dots. In fact, of course, all their angular diameters are different. The angular diameter of Betelgeuse was first determined in 1920 as 0.047 arcseconds, which was the largest angular diameter of a star then known. Since then, however, the star R Doradus, invisible in the northern hemisphere, has been discovered, the angular diameter of which turned out to be 0.057 arcseconds. But even in the southern hemisphere it is almost invisible: at maximum brightness it is hardly visible to the naked eye, and at minimum it can not be seen with every telescope. R Doradus is so cold that it emits mostly infrared radiation. But since then, the angular measurements have been refined, and for Betelgeuse, the apparent diameter is determined from 0.056 to 0.059 arcseconds, which restores to it the lost positions of the largest visible star. It's not so easy to push the queen of winter skies!
Not surprisingly, Betelgeuse was the first star for which disk photographs were taken. That is, on which the star looked not like a point, but a disk. (That the bright stars appear as disks in the above photograph is a convention of the image, which can only convey a difference in brightness by a difference in size.) The photo was taken by the Hubble Space Telescope in 1995.
Here is a historical UV image (NASA/ESA credit):

It is clear that the colors in the photograph are arbitrary: the redder, the colder. A bright spot near the center of the star is considered one of its poles, that is, the axis of rotation of Betelgeuse is directed almost towards us, but slightly to the side.
More recently, namely in July last (2009), new photographs of Betelgeuse were taken with the ground-based Very Large Telescope (VLT) in Chile. Here is one of them:

The resulting photos show that Betelgeuse has a tail. This tail stretches for six radii of Betelgeuse itself (comparable to the distance from the Sun to Neptune). What kind of tail it is, why it is there and what it means, scientists themselves do not yet know, although there are many assumptions.
Measuring Betelgeuse
It is interesting to give the main parameters of Betelgeuse. We will see that in almost all respects, Betelgeuse turns out to be one of the “winners” of the known Universe.
In diameter, as already mentioned, Betelgeuse exceeds the Sun by about a thousand times. It is very difficult to accurately determine the diameter and distance from the Sun of a single star, and no satellites have been found in Betelgeuse (although it is very possible that they are, they just cannot be seen next to such a hulk). But Betelgeuse is so huge that its diameter could be measured "directly", i.e. with the help of an interferometer - this operation could be applied to a very small number of stars, and Betelgeuse was the first.
In terms of mass, Betelgeuse exceeds the Sun by about 15 times (from 10 to 20 - to measure the mass of a single star is generally the aerobatics of astrometry, more precisely, it has not yet been possible). How can it be, a thousand times larger in diameter, which means that it is a billion times larger in volume, and only 15 times larger in mass, what is the density there? But this one. And if we take into account that the core of a star is much denser than its outer layers, then the outer layers of Betelgeuse are much rarer than anything that we can imagine, except for interstellar space, into which Betelgeuse, like almost any star, passes very gradually, i.e. it is impossible to determine exactly where the star ends and interstellar space begins. Nevertheless, fifteen solar masses is quite a lot for a star. Only 120 known stars are heavier than Betelgeuse.
How many times is Betelgeuse brighter than the Sun? One hundred thirty-five thousand times! True, this is taking into account infrared radiation, and in visible light, about a hundred thousand times. That is, if you mentally place Betelgeuse and the Sun at the same distance, Betelgeuse would be a hundred thousand times brighter than the Sun. In the list of the most powerful known stars, Betelgeuse occupies approximately the twenty-fifth position (approximately, because the exact brightness of many hypergiants is not exactly known). If you place Betelgeuse at a standard distance of ten parsecs from the Earth (about 32 light years), then it would be visible during the day, and at night objects would cast shadows in its light. But it’s better not to put it there, because the radiation of a supergiant is such a thing that it’s better for living beings to look at from afar. It seems that the absence of nearby supergiants (of any color) is one of the conditions for life on Earth.
The surface temperature of Betelgeuse is three and a half thousand kelvins (well, ordinary degrees are also close to that). For a star, this is not much; Our Sun has a surface temperature of 5700 K, which is twice as hot. That is, Betelgeuse is a "cold" star, one of the coldest known stars. The temperature of a star determines its color, or rather the shade of its glow. Those mysterious people who manage to see the stars in color unequivocally define the color of Betelgeuse as pronouncedly reddish (see the epigraph). That is why Betelgeuse is called a red supergiant. It is not necessary to think that it really is bright red, like a poppy: rather, its surface is yellowish-orange.

Presumably, this is what the surface of Betelgeuse looks like.

I mentioned above that the apparent diameter of Betelgeuse is from 0.056 to 0.059 arcseconds. This variation is not due to inaccurate measurements. And due to the fact that the body of the star itself pulsates with an approximate period of several years, changing both size and brightness. It would be logical to assume that as the size decreases, the brightness of the star will also decrease, but in fact everything happens exactly the opposite: at the minimum size, Betelgeuse acquires maximum brightness. At maximum brightness, Betelgeuse turns out to be brighter than Rigel, whose magnitude is 0.18, that is, the brightest star in the constellation. Therefore, in terms of brilliance, Betelgeuse is fully entitled to the designation Alpha Orion.
In itself, this is not surprising: the heating of a star during compression is a common place in astrophysics (it occurs due to the transition of gravitational potential energy into kinetic energy, who knows the exact wording, correct me). But why is Betelgeuse so pulsating? What kind of processes are going on inside her? Nobody knows.
The short youth of a giant star
Remember we talked about how young Sirius is, only 250 million years old? So, Betelgeuse is a small child compared to Sirius: she is only 10 million years old! When it caught fire, dinosaurs had already died out on Earth long ago, mammals had already taken the main position on land, the continents had already almost taken on their current outlines, the youngest mountain systems (including the Himalayas) were being erected. Realize that the Ural Mountains are much older than Betelgeuse!
But unlike Sirius, which is not clear where it came from, it is very clear where Betelgeuse came from.
Orion is a unique constellation: the stars in it, not only for our eyes, but in reality are quite close to each other in space. And they are close in age too. The fact is that most of Orion is occupied by a giant nebula - the Molecular Cloud of Orion, in which intensive star formation processes are taking place (that is, it is a “stellar cradle”, besides, almost the closest to Earth). Young stars scatter from this nebula in all directions. Of these young, hot blue stars, exemplary peers, relatively close to the place of their birth, Orion consists.
But if all the other stars in Orion are hot to blue (which is typical for young stars), then why is Betelgeuse red?
Because it's very big.
The lifetime of a star is determined by how long it takes for hydrogen to completely turn into helium in the core of a star it must burn. But here again, the opposite is true: the larger and heavier the star, the higher the temperature in its core and the faster it goes there. thermonuclear reaction. Since Betelgeuse was born heavier and larger than its peers Rigel, Bellatrix and other stars of Orion, the hydrogen in its core burned faster and burned out in just a few million years. And after the burning out of hydrogen in the core, the star enters the dying stage - the transformation into a red giant. In the case of Betelgeuse, it has evolved into a red supergiant.
That is, despite the fact that Betelgeuse is one of the youngest stars in the Universe in terms of age, it is already on the verge of death. Alas, large hot stars do not live very long, outliving their turbulent life in just a few million years. There are several more red hypergiants that have entered the last phase of their development, but they are all very far from us. Therefore, Betelgeuse provides a unique, albeit sad, opportunity to study the last phase of a star's life from a relatively close distance.
Betelgeuse is known to have shrunk in diameter by 15 percent over the past 15 years. This is a constant contraction, not associated with pulsations. Mathematical models of stars say that such a reduction in size is also a sign that the end of the star's evolution is approaching.
What will happen to Betelgeuse next? This is not the peaceful Sirius-Main, now Sirius B, who simply quietly threw off his scarlet shells and turned into a white dwarf. The mass of Betelgeuse is so great that it will have to throw off the shells in one of the grandest explosions that are known to the Universe - in the outbreak of a supernova.
And it will be the closest supernova to the Earth, perhaps for the entire time of the existence of the Earth. Precisely because there is not and has not been a single supergiant closer: supergiants are doomed to end their evolution in supernova explosions, supernova remnants are characteristic and easily identified, and so there is not a single one nearby.
When it will be? Betelgeuse will explode within the next millennium. Possibly tomorrow.
How will it look like? Instead of a shining point in the sky, a disk of dazzling brightness will appear, which will be visible during the day, and at night it will be possible to read by its light. This disk will slowly fade, and the night sky will probably return to normal in a few months. In place of Betelgeuse, a nebula of amazing beauty will appear, which will be visible to the naked eye for several years. Then nothing will be visible.
What will be left of Betelgeuse? Not no white dwarf She's too heavy for that. will remain neutron star(pulsar) or black hole.
How will this affect life on Earth? Most likely not. Betelgeuse is far enough from the Earth that the hard radiation from the supernova burst is dissipated in space without reaching the solar system, and what arrives will be reflected by the solar magnetosphere. Only if the axis of rotation of Betelgeuse was directed directly to the Earth, then hard gamma radiation would painfully whip through the biosphere. But we know from Hubble photographs that Betelgeuse's axis of rotation is away from the Earth. So the heavenly fireworks can be admired from the Earth quite safely.
The same fate awaits Rigel, Bellatrix and the other bright stars of Orion over the next tens of millions of years. Before becoming a red supergiant, Betelgeuse was obviously a hot blue star like them. They will be replaced by young stars, still hidden from us in the depths of the Molecular Cloud of Orion.
So go and watch Betelgeuse while it's still shining. Heaven is not immutable.

largest visible star

On the right shoulder of Orion, in the crown of the Winter Hexagon, the beautiful Betelgeuse shines in the winter skies.

Constellation of Orion. Betelgeuse is a reddish-orange star in the upper left corner of the constellation.

First, Betelgeuse is one of the largest stars in the universe. Its diameter is more than the diameter of the Sun by about a thousand times. Even the largest known star, VY Canis Major, is only twice the diameter of Betelgeuse (and therefore eight times the volume). So it is not in vain that this star bears the proud title of a red supergiant.

If it were in place of the Sun, it would almost fill the orbit of Saturn:

Only eight known stars (all red hypergiants) surpass Betelgeuse in volume, but they all look very dim in the earth's sky. The reason is simple: Betelgeuse is much closer than all of them.

Betelgeuse is 640 light-years away, which is very short on the scale of the Galaxy. Betelgeuse is the closest supergiant to us.

An interesting conclusion follows from this: Betelgeuse in the earth's sky has the largest apparent diameter of all stars (after the Sun, of course.)

It is clear that everything that is less than an arc minute in diameter is perceived by the human eye as a point. The angular diameters of absolutely all stars (except the Sun) are less than an arc minute, so they all look like dots. In fact, of course, all their angular diameters are different. The angular diameter of Betelgeuse was first determined in 1920 as 0.047 arcseconds, which was the largest angular diameter of a star then known. Since then, however, the star R Doradus, invisible in the northern hemisphere, has been discovered, the angular diameter of which turned out to be 0.057 arcseconds. But even in the southern hemisphere it is almost invisible: at maximum brightness it is hardly visible to the naked eye, and at minimum it can not be seen with every telescope. R Doradus is so cold that it emits mostly infrared radiation. But since then, the angular measurements have been refined, and for Betelgeuse, the apparent diameter is determined from 0.056 to 0.059 arcseconds, which restores to it the lost positions of the largest visible star. It's not so easy to push the queen of winter skies!

Not surprisingly, Betelgeuse was the first star for which disk photographs were taken. That is, on which the star looked not like a point, but a disk. (That the bright stars appear as disks in the above photograph is a convention of the image, which can only convey a difference in brightness by a difference in size.) The photo was taken by the Hubble Space Telescope in 1995.

Here is a historical UV image (NASA/ESA credit):

More recently, namely in July last (2009), new photographs of Betelgeuse were taken with the ground-based Very Large Telescope (VLT) in Chile. Here is one of them:

Measuring Betelgeuse

It is interesting to give the main parameters of Betelgeuse. We will see that in almost all respects, Betelgeuse turns out to be one of the “winners” of the known Universe.

In diameter, as already mentioned, Betelgeuse exceeds the Sun by about a thousand times. It is very difficult to accurately determine the diameter and distance from the Sun of a single star, and no satellites have been found in Betelgeuse (although it is very possible that they are, they just cannot be seen next to such a hulk). But Betelgeuse is so huge that its diameter could be measured "directly", i.e. with the help of an interferometer - this operation could be applied to a very small number of stars, and Betelgeuse was the first.

In terms of mass, Betelgeuse exceeds the Sun by about 15 times (from 10 to 20 - to measure the mass of a single star is generally the aerobatics of astrometry, more precisely, it has not yet been possible). How can it be, a thousand times larger in diameter, which means that it is a billion times larger in volume, and only 15 times larger in mass, what is the density there? But this one. And if we take into account that the core of a star is much denser than its outer layers, then the outer layers of Betelgeuse are much rarer than anything that we can imagine, except for interstellar space, into which Betelgeuse, like almost any star, passes very gradually, i.e. it is impossible to determine exactly where the star ends and interstellar space begins. Nevertheless, fifteen solar masses is quite a lot for a star. Only 120 known stars are heavier than Betelgeuse.

How many times is Betelgeuse brighter than the Sun? One hundred thirty-five thousand times! True, this is taking into account infrared radiation, and in visible light, about a hundred thousand times. That is, if you mentally place Betelgeuse and the Sun at the same distance, Betelgeuse would be a hundred thousand times brighter than the Sun. In the list of the most powerful known stars, Betelgeuse occupies approximately the twenty-fifth position (approximately, because the exact brightness of many hypergiants is not exactly known). If you place Betelgeuse at a standard distance of ten parsecs from the Earth (about 32 light years), then it would be visible during the day, and at night objects would cast shadows in its light. But it’s better not to put it there, because the radiation of a supergiant is such a thing that it’s better for living beings to look at from afar. It seems that the absence of nearby supergiants (of any color) is one of the conditions for life on Earth.

The surface temperature of Betelgeuse is three and a half thousand kelvins (well, ordinary degrees are also close to that). For a star, this is not much; Our Sun has a surface temperature of 5700 K, which is twice as hot. That is, Betelgeuse is a "cold" star, one of the coldest known stars. The temperature of a star determines its color, or rather the shade of its glow. Those mysterious people who manage to see the stars in color unequivocally define the color of Betelgeuse as pronouncedly reddish (see the epigraph). That is why Betelgeuse is called a red supergiant. It is not necessary to think that it really is bright red, like a poppy: rather, its surface is yellowish-orange.

Presumably, this is what the surface of Betelgeuse looks like.

In itself, this is not surprising: the heating of a star during compression is a common place in astrophysics (it occurs due to the transition of gravitational potential energy into kinetic energy, who knows the exact wording, correct me). But why is Betelgeuse so pulsating? What kind of processes are going on inside her? Nobody knows.

The short youth of a giant star

Remember we talked about how young Sirius is, only 250 million years old? So, Betelgeuse is a small child compared to Sirius: she is only 10 million years old! When it caught fire, dinosaurs had already died out on Earth long ago, mammals had already taken the main position on land, the continents had already almost taken on their current outlines, the youngest mountain systems (including the Himalayas) were being erected. Realize that the Ural Mountains are much older than Betelgeuse!

But unlike Sirius, which is not clear where it came from, it is very clear where Betelgeuse came from.

Orion is a unique constellation: the stars in it, not only for our eyes, but in reality are quite close to each other in space. And they are close in age too. The fact is that most of Orion is occupied by a giant nebula - the Molecular Cloud of Orion, in which intensive star formation processes are taking place (that is, it is a “stellar cradle”, besides, almost the closest to Earth). Young stars scatter from this nebula in all directions. Of these young, hot blue stars, exemplary peers, relatively close to the place of their birth, Orion consists.

But if all the other stars in Orion are hot to blue (which is typical for young stars), then why is Betelgeuse red?

Because it's very big.

The lifetime of a star is determined by how long it takes hydrogen to completely convert to helium in the star's core. (people, educational program about why the stars are burning, do you need to write?) It would seem that the larger and heavier the star, the more hydrogen it contains, and the longer it should burn. But here again, the opposite is true: the larger and heavier the star, the higher the temperature in its core and the faster the thermonuclear reaction goes there. Since Betelgeuse was born heavier and larger than its peers Rigel, Bellatrix and other stars of Orion, the hydrogen in its core burned faster and burned out in just a few million years. And after the burning out of hydrogen in the core, the star enters the dying stage - the transformation into a red giant. In the case of Betelgeuse, it has evolved into a red supergiant.

That is, despite the fact that Betelgeuse is one of the youngest stars in the Universe in terms of age, it is already on the verge of death. Alas, large hot stars do not live very long, outliving their turbulent life in just a few million years. There are several more red hypergiants that have entered the last phase of their development, but they are all very far from us. Therefore, Betelgeuse provides a unique, albeit sad, opportunity to study the last phase of a star's life from a relatively close distance.

Betelgeuse is known to have shrunk in diameter by 15 percent over the past 15 years. This is a constant contraction, not associated with pulsations. Mathematical models of stars say that such a reduction in size is also a sign that the end of the star's evolution is approaching.

What will happen to Betelgeuse next? This is not the peaceful Sirius-Main, now Sirius B, who simply quietly threw off his scarlet shells and turned into a white dwarf. The mass of Betelgeuse is so great that it will have to throw off the shells in one of the grandest explosions that are known to the Universe - in the outbreak of a supernova.

And it will be the closest supernova to the Earth, perhaps for the entire time of the existence of the Earth. Precisely because there is not and has not been a single supergiant closer: supergiants are doomed to end their evolution in supernova explosions, supernova remnants are characteristic and easily identified, and so there is not a single one nearby.

When it will be? Betelgeuse will explode within the next millennium. Possibly tomorrow.

How will it look like? Instead of a shining point in the sky, a disk of dazzling brightness will appear, which will be visible during the day, and at night it will be possible to read by its light. This disk will slowly fade, and the night sky will probably return to normal in a few months. In place of Betelgeuse, a nebula of amazing beauty will appear, which will be visible to the naked eye for several years. Then nothing will be visible.

What will be left of Betelgeuse? No, not a white dwarf - it's too heavy for that. There will be a neutron star (pulsar) or a black hole.

How will this affect life on Earth? Most likely not. Betelgeuse is far enough from the Earth that the hard radiation from the supernova burst is dissipated in space without reaching the solar system, and what arrives will be reflected by the solar magnetosphere. Only if the axis of rotation of Betelgeuse was directed directly to the Earth, then hard gamma radiation would painfully whip through the biosphere. But we know from Hubble photographs that Betelgeuse's axis of rotation is away from the Earth. So the heavenly fireworks can be admired from the Earth quite safely.

The same fate awaits Rigel, Bellatrix and the other bright stars of Orion over the next tens of millions of years. Before becoming a red supergiant, Betelgeuse was obviously a hot blue star like them. They will be replaced by young stars, still hidden from us in the depths of the Molecular Cloud of Orion.

Other photos of the star can be found.

> Betelgeuse

Betelgeuse- the second brightest star in the constellation Orion and a red supergiant: description and characteristics with photos, facts, color, coordinates, latitude, supernova.

Betelgeuse(Alpha Orionis) is the second brightest star in Orion and the 9th in the sky. It is a red supergiant, 643 light years distant. Ends its existence and will explode as a supernova in the near future.

Before you is a large, bright and massive star, which is easy to see in the winter. Lives in the shoulder of the constellation Orion opposite Bellatrix. You will know where the Betelgeuse star is if you use our online star map.

Betelgeuse is considered a variable star and periodically outshines Rigel. The name comes from the Arabic translation "hand of Orion". Modern Arabic "al-Jabbar" means "giant". The translators confused Y for B and the name "Betelgeuse" appeared only as a mistake. Further you will learn about the distance to the star Betelgeuse, its latitude, coordinates, class, declination, color and luminosity level with photos and diagrams.

Betelgeuse is in Orion's right shoulder (top left). If placed in our system, it will go beyond the asteroid belt and touch the orbital path of Jupiter.

Refers to the spectral type M2Iab, where "lab" indicates that we are dealing with a supergiant with an intermediate luminosity. The absolute value reaches -6.02. The mass fluctuates between 7.7-20 times that of the sun. The age is 10 million years, and the average luminosity is 120,000 times the solar indicator.

The apparent value changes from 0.2-1.2 in 400 days. Because of this, it periodically bypasses Procyon and takes the 7th position in terms of brightness. At the peak of luminosity, Rigel outshines, and at the dim period it falls below Deneb and becomes the 20th.

The absolute value of Betelgeuse varies from -5.27 to -6.27. The outer layers expand and contract, causing temperatures to rise and fall. The pulsation occurs due to the unstable atmospheric layer. When absorbed, it absorbs more energy.

There are several pulsation cycles with short-term differences of 150-300 days, and long-term ones cover 5.7 years. The star is rapidly losing mass, so it is covered by a huge shell of material, which makes it difficult to observe.

In 1985, two satellites were noticed in orbit around the star, but then they could not be confirmed. Betelgeuse is easy to find because it is located in Orion. From September to March, it is visible from any point on Earth, except for 82°S. For residents of the northern hemisphere, the star will rise in the east after sunset in January. In summer, she hides behind the Sun, so she cannot be seen.

Supernova and star Betelgeuse

Betelgeuse has come to the end of its evolutionary development and will explode as a type II supernova in the next million years. This will result in a visual magnitude of -12 and last for a couple of weeks. The last supernova, SN 1987A, could be seen without instruments, although it occurred in the Large Magellanic Cloud, 168,000 light-years distant. Betelgeuse will not harm the system, but will give an unforgettable celestial spectacle.

Although the star is young, it has practically used up its fuel supply. Now it shrinks and increases internal heating. This resulted in the melting of helium into carbon and oxygen. As a result, an explosion will occur and a 20-kilometer neutron star will remain.

The final star always depends on the mass. The exact figure remains vague, but many believe that it exceeds the Sun by 10 times.

Facts about the star Betelgeuse

Let's look at interesting facts about the star Betelgeuse with a photo and a view of the stellar neighbors in the constellation of Orion. If you want more details, then use our 3D models that allow you to independently move among the stars of the galaxy.

Included in two winter asterisms. Occupies the upper corner of the Winter Triangle.

The remaining corners are assigned to Procyon and Sirius. Betelgeuse is also part of the Winter Hexagon along with Sirius, Procyon, Pollux, Capella, Aldebaran and Rigel.

In 2013, it was thought that Betelgeuse would crash into a "cosmic wall" of interstellar dust in 12,500 years.

Betelgeuse is part of the Orion OB1 Association, whose stars share regular motion and uniform speed through space. The red supergiant is thought to have changed its course because its path does not intersect with star-forming regions. May be a runaway member that appeared about 10-12 million years ago in the Orion molecular cloud.

The star moves in space with an acceleration of 30 km/s. As a result, a shock wave was formed with a length of 4 light years. The wind pushes huge gas volumes at a speed of 17 km / s. They managed to display it in 1997, and the formation is about 30,000 years old.

Alpha Orionis is the brightest near-IR source in the sky. Only 13% of the energy is displayed in visible light. In 1836, John Herschel noted stellar variability. In 1837, the star eclipsed Rigel and repeated this in 1839. It was because of this that in 1603 Johann Bayer mistakenly gave Betelgeuse the designation "alpha" (as the brightest).

The star Betelgeuse is believed to have begun existence 10 million years ago as a hot blue O-type star. And the initial mass exceeded the solar mass by 18-19 times. Until the 20th century, the name was recorded as "Betelje" and "Betelgeuse".

Betelgeuse has been fixed in various cultures under different names. In Sanskrit, it is written as "bahu", because the Hindus saw a deer or an antelope in the constellation. In China, Shenksia is the "fourth star" as a reference to Orion's belt. In Japan - Heike-boshi as a tribute to the Heike clan, who took the star as a symbol of their kind.

In Brazil, the star was called Zhilkavai - a hero whose wife tore his leg. In northern Australia, she was nicknamed "Owl Eyes", and in southern Africa - a lion hunting for three zebras.

Betelgeuse is also featured in various feature films and books. So the hero of "Beetlejuice" shares a name with the star. Betelgeuse became the home system for Zaford Beeblebrox from The Hitchhiker's Guide to the Galaxy. Kurt Vonnegut has a star in Titan's Sirens, as does Pierre Boulle in Planet of the Apes.

Betelgeuse star size

It is difficult to determine the parameters, but the diameter covers approximately 550-920 solar. The star is so huge that it exhibits a disk in telescopic observations.

The radius was measured using an infrared spatial interferometer, which showed a mark of 3.6 AU. In 2009, Charles Townes announced that since 1993, the star has shrunk by 15%, but has not lost its brightness. Most likely, this is caused by the activity of the shell in the extended atmospheric layer. Scientists have found at least 6 shells around the star. In 2009, a gas release was recorded at a distance of 30 AU.

Alpha Orionis became the second star after the Sun, where it was possible to calculate the angular size of the photosphere. This was done by A. Michelson and F. Paise in 1920. But the numbers were inaccurate due to attenuation and measurement errors.

The diameter is difficult to calculate due to the fact that we are dealing with a pulsating variable, which means that the indicator will always change. In addition, it is difficult to determine the stellar edge and photosphere, since the object is surrounded by a shell of ejected material.

It was previously believed that Betelgeuse has the largest angular diameter. But later they did a calculation in R Doradus and now Betelgeuse is in 3rd place. In radius, it extends to 5.5 AU, but can be reduced to 4.5 AU.

Distance of the star Betelgeuse

Betelgeuse resides 643 light years away in the constellation Orion. In 1997, it was believed that the indicator was 430 light years, and in 2007 they put it at 520. But the exact figure remains a mystery, because direct measurement of parallax shows 495 light years, and the addition of natural radio emission shows 640 light years. Data from 2008 taken by the VLA suggested 643 light years.

Color index - (B-V) 1.85. That is, if you wanted to know what color Betelgeuse is, then we have a red star.

The photosphere has an expanded atmosphere. As a result, blue emission lines appear, not absorption lines. Even ancient observers knew about the red color. So Ptolemy in the 2nd century gave a clear description of the color. But even 3 centuries before him, Chinese astronomers described the color yellow. This does not indicate an error, because earlier the star could be a yellow supergiant.

Betelgeuse star temperature

The surface of Betelgeuse warms up to 3140-4641 K. The atmospheric index is 3450 K. The gas cools with expansion.

Physical characteristics and orbit of the star Betelgeuse

Betelgeuse is the Alpha of Orion.
Constellation: Orion.
Coordinates: 05h 55m 10.3053s (right ascension), + 07° 24" 25.426" (declination).
Spectral type: M2Iab.
Magnitude (visible spectrum): 0.42 (0.3-1.2).
Value: (J-band): -2.99.
Absolute value: -6.02.
Distance: 643 light years.
Variable type: SR (semi-regular variable).
Massiveness: 7.7-20 solar.
Radius: 950-1200 solar.
Luminosity: 120,000 solar.
Temperature mark: 3140-3641 K.
Rotation speed: 5 km/s.
Age: 7.3 million years.
Name: Betelgeuse, Alpha Orioni, α Orioni, 58 Orona, HR 2061, BD + 7° 1055, HD 39801, FK5 224, HIP 27989, SAO 113271, GC 7451, CCDM J05552+0724AP, AAVSO 0549+07.

Betelgeuse (α Orioni) 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 and averages about 0.7 m. The red color of the star, easily visible when observed with the naked eye, corresponds to the indicator colors B-V= 1.86m. 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 were placed in the place of the Sun, then at a minimum size it would fill the orbit of Mars, and at a maximum size it would reach the orbit of Jupiter.

The angular diameter of Betelgeuse, according to modern estimates, is about 0.055 arc seconds. 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 17 solar masses.

Comparison of the sizes of the Sun and Betelgeuse

Presumably, the name comes from the distorted Arabic “Yad al Jawza” (“twin’s hand” or even his “armpit”), which in medieval Latin, due to a copyist’s mistake who did not know the intricacies of translation from Arabic, was first transformed into Bedalgeuze, and then gradually into the present day. famous Betelgeuse.

Do not confuse the modern constellation Gemini with the Arabic one. Orion, in which Betelgeuse is located, was part of Gemini among the Arabs.

An interesting fact is that over 16 years of observations since 1993, the radius of Betelgeuse has decreased by as much as 15 percent, while its brightness has not changed. Scientists have not yet given a clear answer why this happened. Versions are put forward both about the inaccuracies of the observations of the star, and that it may have irregular shape and simply during the observation turned to us the other side. Since Betelgeuse is as much as 570 light-years distant from the Sun, it is not possible to collect more accurate data on its characteristics at the moment.

The future of the star is also very vague. Perhaps the fate of a supernova awaits her, or perhaps this red supergiant will be lucky and she will throw off her shell in the form of a planetary nebula, and she herself will turn into a white dwarf. If the star is destined to explode, then a supernova comparable in brightness to the Moon will be observed on Earth for several months, and then the star will disappear forever for earthlings, but after centuries a nebula will become visible in this place.

However, if one of Betelgeuse's poles points towards Earth, there will be more tangible impacts. A stream of gamma rays and other cosmic particles will be sent to the Earth. There will be strong aurorae and possibly a measurable decrease in the amount of ozone in ozone layer with consequent adverse effects on life on the planet. In this orientation towards solar system the flash will also be many times brighter than if the axis of the star is pointing away from us.

In 1980, Shu-ren, Jianming and Jin-yi found Chinese reports dating back to the 1st century BC during excavations. e., from which it follows that the color of Betelgeuse is white or yellow. At the same time, Ptolemy in 150 AD. e. describes it as a red star. Fang Lizhi, a Chinese astrophysicist, suggested that Betelgeuse may have turned red giant star while. Stars are known to change their color from white to yellow to red after they use up the hydrogen in their cores. Shu-ren suggested that Betelgeuse may have changed its color when she shed the shell of dust and gas that is visible even now and is still expanding. Thus, if their version is correct, it is unlikely that Betelgeuse will soon go supernova, because the star usually remains a red giant for tens of thousands of years.