The constellation Gemini is one of the most ancient constellations that were included in Claudius Ptolemy’s monograph “Almagest” in the 2nd century AD. There were 48 of them in total, and 12 of them were considered zodiac. They were located on the ecliptic. It was along it that the Sun made its annual circuit of the celestial sphere. This is what the ancient Greeks believed. In our time, little has changed: astronomers are very conservative and have great respect for ancient traditions. Only there were 88 constellations instead of 48.
The constellation in question is a zodiacal one. The sun "passes through it" from June 20 to July 20. This cluster of stars is located in the Northern Hemisphere of the celestial sphere between Cancer in the east and Taurus in the west. In the north are the Charioteer and the Lynx, and in the south are the Unicorn and the Small Dog. The company is quite decent and intelligent. So there is no need to worry about the twins.
The constellation Gemini surrounded by other constellations
The brightest stars in this constellation are Castor and Pollux. These are the so-called heads of twins, facing northeast. And their feet stand directly on the Milky Way. It seems that the brothers, holding hands tightly, are walking through a pale heavenly haze.
Star Pollux brighter than Castor, although it is designated beta. This is an orange giant that has already left the Main Sequence. It has no more than 100 million years left to exist. After this, it should turn into a white dwarf.
The mass of the orange giant is 2 times greater than the Sun, and its radius is 9 times greater. The distance to Earth is 33.78 light years. Magnetic activity is low. The most interesting thing is that an exoplanet was discovered near Pollux.
Star Castor is the "head of the second twin". In terms of brightness, it ranks 2nd in the constellation. It is located 49.8 light years from Earth. Castor is a multiple star consisting of 6 components. These are Castor A, Castor B and Castor C. Castor A and Castor B are spectroscopic double stars. They mean 2 stars connected by gravity and revolving around the same center of mass.
Castor C is the conventional name for the variable star YY Gemini. It is also a spectroscopic binary and is gravitationally dependent on the first 2 components. It takes several tens of thousands of years to complete a revolution around them. But Castor A and Castor B orbit each other in 350 years. Thus, the system is complex, but quite typical for space.
Other stars located in the constellation Gemini are also of interest. The third brightest is the Gemini gamma. It's called Alhena and is located 109 light years from Earth. This is a subgiant. Its mass is 2.8 times that of the sun. And the radius is 3.3 times greater than that of the Sun. This is a spectroscopic binary system with a luminosity 123 times greater than the Sun.
Delta Gemini is located almost on the ecliptic. Has the name Wasat, which means "middle" in Arabic. From Earth it is visible to the naked eye, but is often obscured by the Moon and rarely by other planets of the Solar System. It is a subgiant located 60.5 light years from Earth. The age of the star is 1.6 billion years. A triple star, where 2 components form a spectroscopic binary system, and the third component is their satellite.
The double system U Gemini is of interestmoon. It is notable for the fact that it consists of 2 stars: red and white dwarfs. They are located very close to each other. A red dwarf has a circumstellar disk. Its diffusive material flows onto the white dwarf. As a result, an explosion occurs every 100 days, which is a flash that lasts about 2 days. The distance to U Gemini from Earth is 270 light years.
The constellation Gemini has nebulae and open star clusters. Of the nebulae we can call Eskimo And Medusa. Medusa is on the border with Canis Minor. And the Eskimo (NGC 2392) resembles a human head with a hood over it. It is separated from Earth by a distance of 2870 light years.
open cluster M35 is located 2800 light years from Earth. It is located in the western part of Gemini. Through binoculars it appears as a dark spot with several faint stars. And through a telescope you can see dozens of white stars scattered throughout the cosmic abyss. Open clusters can also be named NGC 2129, NGC 2158, NGC 2355, but this is not the entire list.
Concerning ancient greek mythology, then Leda, the wife of the Spartan king Tyndareus, once met Zeus on the Eurotas River. He was struck by her beauty, but in order to seduce the married woman, he appeared before her in the form of a swan. The Thunderer took possession of Leda, and she laid 2 eggs, from which the twins Castor and Polydeuces emerged. When they grew up, they became courageous warriors.
They took part in the Argonauts' campaign, performed successfully at the Olympic Games, and accomplished many other glorious feats. They were seen as gods of dawn and evening twilight, and the twins' military prowess was an example to be followed. They entered mythology as the Dioscuri. Therefore, it is not at all surprising that the impressionable Greeks placed the constellation Gemini in the sky. Thus, they once again paid tribute to courage and valor.
As for the stars Castor and Pollux, everything is clear with the first one. But Pollux is the Latin form of the name Polidevka. Since ancient times, these two luminaries have reminded people of the good deeds of mythological heroes and their loyalty to their duty.
The article was written by Maxim Shipunov
The constellation Gemini is one of the most famous, perhaps due to the fact that it belongs to the zodiac. In the sky, it does not look very impressive, although its two main stars, Castor and Pollux, are quite bright and easy to find. And in this constellation there are very interesting objects to observe.
The constellation Gemini has been known since ancient times, and of course there are corresponding myths about it. According to ancient Greek mythology, the main stars of the constellation - Castor and Pollux, personify two brothers - twins. They were born by the queen of Sparta Leda, who was famous for her beauty, which even the god Zeus could not resist. Turning into a swan so that he would not be recognized by the divine wife Hera, he entered Leda through the window, and as a result, Leda gave birth to Pollux and Helen from him. Another name for Pollux is Polydeuces, which is what the Romans called him. And Helen, by the way, divinely beautiful, later became the cause of the Trojan War.
At the same time as Pollux and Helen, Leda also gave birth to two more children - a son, Castor, and a daughter, Clytemnestra. However, their father was Leda's legal husband - the king of Sprata named Tindarus. Therefore, Castor was an ordinary mortal man, and Pollux was immortal, for he had a divine parent who took care of this.
Castor and Pollux grew up together and eventually became renowned heroes. They took part in the famous campaign of the Argonauts and accomplished many feats. Pollux was a famous fist fighter, and Castor was a master of horsemanship and fencing - according to legend, he trained Hercules himself. The twins loved each other very much and were always together.
But one day a tragedy happened. Castor and Pollux had two cousins, also twins - Lynceus and Ides. In a quarrel, Id hit Castor with a spear and killed him. Pollux grappled with Id, but the forces were equal, and the fight dragged on until Zeus threw lightning, which struck the offender.
Pollux's grief was so great that he asked his divine father to strip him of his immortality so that he could follow his brother to the underworld of the dead of Hades. As a result, they agreed on a compromise solution - Pollux would spend one day with his brother in the kingdom of Hades, and the second day the two of them would ascend to the gods on Mount Olympus.
Castor and Pollux are two inseparable brothers.
So the brothers ended up in the sky, becoming stars that remind people of true brotherly love. The ancient Greeks revered them as gods who protected travelers from all troubles in foreign countries.
Pollux (left) and Castor (right) - this is how they look in the sky.
This is such an interesting story, full of passions, connected with the constellation Gemini.
Constellation Gemini in the sky (Stellarium planetarium).
Attractions of the constellation Gemini
There are several objects in this constellation that can be observed with the naked eye or with a small telescope. There are several curious stars, as well as one open star cluster that is part of - M35. About 70 stars can be seen with the naked eye in Gemini on a dark night, with part of the constellation falling in the Milky Way.
Stars of the constellation Gemini
Several stars deserve special attention here: Castor And Pollux, and there are also variable and double stars.
Castor - alpha of the constellation Gemini
It’s worth noting right away that although Castor is designated by the letter “alpha,” in fact it is not the brightest star in Gemini - Pollux, which is designated by the letter “beta,” is brighter than it. The brightness of Castor is 1.59m, and Pollux is 1.16m.
Castor is an amazing star. If you look at it through a small telescope, for example, a refractor with an aperture of 70-90 mm, you will notice that this star is actually a double star - the angular distance between its components is 4”. These blue components (A and B), with brightnesses of 2.0 and 2.9m, are separated from each other by a distance of orbiting around a common center of mass in about 350 years. The fact of Castor duality was established by William Herschel in 1804, and he also calculated the period of orbital motion of stars in the system.
But that is not all. In fact, each component - A and B, is actually a double too! It will not be possible to see this, since they are located very close to each other - the distance between them is 6 times less than the distance from Mercury to the Sun. Stars in such systems must rotate in orbit very quickly and, under the influence of mutual attraction, take on the shape of ellipses.
Components A and B in the Castor system are similar to each other. Each consists of a pair of stars - a hot white star with about 2 solar masses, and a red dwarf with 0.7 solar masses.
But that's not all! At a distance of 73" from these two stars you can find a dim star with a brightness of 9m, which even has its own designation - YY Gemini. So this star is the third component of Castor, which also rotates with the first two around a common center of mass; the period here, due to its great distance, is tens of thousands of years. Over a century and a half of observations, it has not yet been possible to detect the motion of Castor C relative to other components of the system, it is so small.
Castor system. Each of the 3 bright stars here is also a close binary system. Screenshot from the Space Engine program.
But this is not enough - in fact, Castor C is also a double star, and a very close one. Here is a pair of red dwarfs with a mass of about 0.6 solar, located only 2.7 million kilometers from each other. Moreover, their orbits are located in such a way that we see Castor C as an eclipsing variable star with a period of 19 days.
Such an amazing twin is Castor, alpha Gemini, a system of 6 suns, two white hot stars and four red dwarfs, almost 50 light years away from us. Once every few tens of thousands of years, all the stars come together, and if there were planets there, the sky on them would look very interesting.
Pollux – Beta Gemini
After the majestic picture of Castor's sixfold system, Pollux is not particularly surprising. It is the brightest star in the constellation Gemini, with a brightness of 1.15m and a distance of 33.7 light years from us.
In fact, Pollux is a typical red giant, having practically exhausted all its helium, and in the next hundred million years it will shed its shell and turn into a white dwarf.
In 1993, this star was suspected of having a planet. In 2006, an exoplanet with twice the mass of Pollux was actually discovered. When a competition was announced for the name of this planet, it was proposed to name it Leda, in honor of the twins' mother. But since an asteroid and one of Jupiter’s satellites have already been named by this name, the planet was named Thestias. This is what it looks like in the program):
Exoplanet Thestias in the rays of Procyon. Screenshot from the Space Engine program.
If there are any other planets or satellites there, especially inhabited ones, then a catastrophe awaits their inhabitants in the near future.
Other interesting stars of the constellation Gemini
This constellation contains an eclipsing variable star, designated as U Gemini. This system consists of red and white dwarfs, which are located so close to each other that matter flows from the red star to the white one. They complete an orbital revolution in just 4 hours and 11 minutes. When a lot of “alien” matter accumulates on the surface of a white dwarf, thermonuclear reactions begin in it, causing the star to flare brightly.
Because of this phenomenon - flashes of brightness, John Russell Hind, an English astronomer, mistook this star for a nova in 1855. However, it later turned out that these outbreaks were repeated. The usual brightness of U Gemini is approximately 14.2m, that is, it can be seen in a fairly serious telescope with an aperture of 150 mm. During the flare, the brightness reaches 8.8m, that is, this star can be seen in any telescope or even in good binoculars. Such outbreaks are repeated after different times - from 62 to 257 days.
Delta Gemini(Vasat) is a double star, and a physical one, where the components are actually connected to each other by gravity. The angular distance between the yellow subgiant and the red dwarf with a brightness of 8.2m is 6.8”. There is an assumption that the bright component itself is a close pair, then it is a triple star.
Star ζ Gemini(Mekbuda) - from the Cepheid class. This is a supergiant, 1200 light years away from us, varying in brightness from 3.7 to 4.2m with a period of 10.2 days.
Star cluster M35
An open star cluster can be found in the western part of the constellation Gemini M35. It has a brightness of 5.3m and with good vision on a dark night you can try to find it with the naked eye. Through binoculars it appears as a hazy speck with several individual stars.
If you have a telescope, the M35 cluster can be examined in more detail. Moreover, in a telescope with a small aperture and low magnification, this cluster looks even more spectacular, due to the larger field of view. This object greatly impressed the famous 19th century astronomer Lascelles. And it can rightfully be called the pearl of the constellation Gemini.
Open star clusters M35 (left) and NGC 2158 (bottom right)
There is another open cluster near M35 - NGC 2158 brightness 8.6m. It is fainter and denser and to resolve it into stars requires a telescope with a larger aperture and magnification, although without details it can be seen at 80-90 mm.
Not far from M35 there are several nebulae that fit perfectly into the frame when photographing together, but this requires a telescope with a large aperture.
In what constellation do the stars Castor and Pollux shine? and got the best answer
Answer from Yergey Kuznetsov[guru]
In Gemini
Answer from 2 answers[guru]
Hello! Here is a selection of topics with answers to your question: In which constellation do the stars Castor and Pollux shine?
Answer from Alexander[guru]
Castor is the second brightest star in the constellation Gemini. And one of the brightest stars in the night sky. Although she is considered a Gemini alpha, she is actually less bright than the Gemini beta Pollux.
Reply from [guru]
The stars Castor (α Gemini) and Pollux (β Gemini), located at a distance of 4.5°, represent the heads of the Dioscuri twins, whose feet, facing southwest, stand on the Milky Way, adjacent to Orion.
Castor is a visual triple system, with both of its bright components being spectroscopic binaries and its faint component an eclipsing binary. Thus, Castor is a cluster of six stars. Their total apparent magnitude is 1.59m and their distance from the Sun is 45 sv. years. Two bright blue-white components with apparent magnitudes 2 and 2.7 form a visual binary with an angular separation of 6″, orbiting a common center of mass with a period of about 400 years. Each of the components is a binary system with orbital periods of 9.2 and 2.9 days. The third component is 73″ away from them, consists of two red dwarfs and is an eclipsing binary, changing its brightness from 8.6 to 9.1 magnitude with a period of 0.8 days.
The magnitude of orange Pollux is 1.16m, the distance is 35 light years; its luminosity is 35 times higher than the sun.
Although Castor shines fainter than Pollux, Bayer designated it α Gemini. This is explained by the fact that when numbering stars of the same constellation that were close in brightness, Bayer left priority to the more northern one.
Gemini is one of the zodiacal constellations of the night sky, known to people even before our era. It is clearly visible in the Northern Hemisphere from December to May. In clear, cloudless weather, you can see up to 70 stars, the brightest of which are Pollux and Castor.
Constellation Gemini
The Dioscuri twins Castor and Pollux are heroes of ancient Greek mythology. They took part in the campaign of the Argonauts, the Calydonian hunt and the Olympic Games, which were organized by Hercules. In Ancient Greece they were considered the saviors of sailors and patrons of warriors, in Rome they were a symbol of military courage.
The constellation was already known in antiquity, and was indicated in the “Almagest” of Claudius Ptolemy. According to legend, Zeus placed him in the sky so that the brothers attached to each other would never separate. The Arabs also compared these stars to Gemini. They called the star Pollux “the head of the second twin.”
In the sky, the Constellation appears at latitudes from +90 to -54 degrees. It covers an area of 514 square degrees, and is in the “company” of Cancer, Lynx, Canis Minor, Taurus, Auriga, Orion and Unicorn.
Alpha Gemini
Castor (α Gem) is the alpha and second brightest star in the constellation Gemini. According to its spectral type, it is characterized as A2Vm - a blue main sequence star. Its radius is almost three times that of the Sun, and its temperature is about 9000 Kelvin. It is 50 light years away from our planet. The apparent magnitude of the star is 1.58, absolute - 0.59/0.61. In this case, the smaller the digital value, the larger the value.
The Castor star is multiple; this feature was noted back in the 17th century. Later it turned out that it is not just a double star, but is a system of three components, each of which is a spectroscopic double star. The largest is Castor a, directly related to Castor b. Their circulation period is about 350 years.
There is a so-called “moving group of Castor stars”. These are 15 stars that are united with Alpha Gemini by the gravitational field and move with it in the same direction. They have different sizes, but the same origin and almost the same age. The Castor group includes the star Vega, Fomalhaut, k Phoenix, α Cephei, 14 Hare, several stars Libra and Gliese.
Beta Gemini
Marking stars with letters of the Greek alphabet was invented by astronomer Johann Bayer, who lived in the 16th-17th centuries. According to his system, the greater the brilliance (apparent brightness) of the luminaries, the older the letter in the alphabet. Thus, alpha is the most noticeable star in the sky, and then in descending order.
But with Pollux it turned out completely differently. This is one of the brightest in the constellation Gemini. However, it is in second place and is listed as “beta”. And all due to the fact that it is located south of Castor on the ecliptic coordinate system.
Among all the visible luminaries of the night sky, the star Pollux ranks 17th in terms of its brilliance. Thus, she is superior to Alpha Leo, Southern Pisces and Swan, as well as Beta of the Southern Cross. It can be observed with the naked eye, without additional optical instruments.
Characteristics of Pollux
The star is an orange giant and belongs to the spectral class K0 IIIb. Its temperature is 4865 degrees Kelvin, and its absolute temperature is 1.09. All these characteristics indicate that the star Pollux is in the last stages of evolution.
It has already moved away from it; hydrogen no longer participates in thermonuclear reactions, remaining “passive.” However, the core, made of helium, still supports the reactions. Over time, the supply of helium will come to an end, and the star, having contracted and shed its shell, will turn into a white dwarf with a very weak glow. Such a transformation must occur within 100 million years.
Now Pollux's luminosity is 32 times greater than the Sun's, and it is about forty light years away from us. It is assumed that it is a variable star, that is, its brightness is not constant and ranges from 1.10 m to 1.17 m. Eleven years ago, scientists discovered that there is an exoplanet in its orbit, which revolves around it with a period of 590 Earth days.
Other objects in the constellation
In addition to Pollux and Castor, there are 12 more stars in Gemini, brighter than the third magnitude, and several dozen more have a magnitude brighter than 6.5 m. Planets have been discovered on about four of them. Gemini is an ideal constellation for observing; a huge number of its objects can be seen even without a telescope, for example, the orange k Gemini together with a green satellite or the spectroscopic double Alhena.
Another interesting star visible to the naked eye is Eta Gemini or Propus. It is a triple with a period of 2.983 Earth days. It is located 380 light years away from the Sun. It has a variable brightness from 3.1 m to 3.9 m. It is quite possible to trace the transition from one value to another by observing the star for 233 days.
The star HD 50692 or 37 Gemini is a yellow dwarf, like our Sun. It is located 56 light years from Earth. Its age exceeds 5.5 billion years, and its mass is almost equal to the Sun. In 2001, a message was sent to her system from a Crimean radar. It will be delivered to the target in 2057.
Geminid streams
From December 4 to 17, the Geminid meteor shower, named after the Latin name of the constellation Gemini, passes near the star Castor. It has been known since the 19th century. Its average speed is 35 km/h. It is not too large, since the meteors move in the same direction as the Earth.
The flow is considered one of the most powerful. Bright fireballs and meteors often appear there. The Geminids peak on December 13-14, when about a hundred meteors pass by in an hour. In 2011 there were 200 per hour.