> Arcturus
Arcturus- the brightest star in the constellation Bootes: description and characteristics with a photo, interesting facts, location, distance, what color, comparison with the Sun.
Arcturus(Alpha Bootes) - the brightest star in the constellation Bootes and the 4th in the sky. With an apparent magnitude of -0.04, it is also in first place in terms of brightness in the northern celestial hemisphere and only slightly exceeds Vega. Lives at a distance of 36.7 light years from us.
It is located in the left foot of the constellation Bootes. Before us is an orange giant (K1.5 IIIpe, where "pe" - special emissions). The absolute value reaches -0.30, which makes it the brightest K-class giant.
The name Arcturus is taken from the Greek "Αρκτοῦρος" and translates as "Guardian/observer of the bear" (meaning the constellation Ursa Major).
Scientists believe that the star has already used up the hydrogen reserve in the core and is now burning the active hydrogen shell. Arcturus will continue to grow in size until it enters the horizontal branch phase. As a result, it will eject the outer layer and leave a white dwarf with a planetary nebula. The approximate age is 7.1-8.5 billion years.
The level of visual luminosity is 113 times greater than that of the sun. If we take into account the IR glow, then more than 180 times. Arcturus has no confirmed planets.
Finding the star Arcturus is not difficult. It is located 20 degrees north of the celestial equator and is observed from both hemispheres. You can follow from the handle of the Big Dipper. Will be the first bright star along the imaginary line drawn. The best time for observation is spring and autumn. Our star chart will help you find Arcturus on your own through a telescope. Or use online 3D models to study the appearance and position of a star in outer space.
Facts about the star Arcturus
Let's look at interesting facts about the star from the constellation Bootes. Arcturus became the first distant star to be observed during the day through a telescope. This was done by Jean-Baptiste Maurin in 1635. It can be seen without the use of technology before sunset.
Arcturus has a low level of metallicity, which means that we have an extremely ancient object. Population II stars occupy approximately 4% of the total stellar volume in the vicinity of our system. Along with the other 52 old stars, Arcturus has regular motion, and the group is called the Arcturus Stream. While all the stars move in a single stream, these go perpendicularly across the disk. As a result, after millions of years, Arcturus will simply disappear from our field of vision.
It is also believed that celestial bodies from the Arcturus Stream entered our system after the Milky Way crashed into a dwarf galaxy 5 billion years ago. The star came to us 500,000 years ago and tries the same amount more, after which it will move in the direction of the constellation Virgo.
A radial velocity study in 1988 showed that the star exhibits variability at a frequency of a few microhertz. Scientists believe that the surface wobbles a little, which is a common feature for red giants. Refers to a new suspicious variable and is designated as NSV 6603.
The star is moving at an acceleration of 122 km/s. Her movement was first recorded by Edmond Halley in 1718. The closest approach to the Sun will be in about 4000 years.
Ancient observers knew about Arcturus. In Mesopotamia, it was the god Enlil - "yoke". Ptolemy described the star as "a little red", and the Romans believed that its arrival heralds a change in the weather.
The Chinese called her Da Zhao - "great horn", and the Japanese - Mugi-boshi, responsible for the wheat harvest. For Hawaiians, this is the zenith star.
An interesting story is connected with the Polynesians, who called Arcturus the "star of joy." They used it in swimming when they crossed the equator in their kayaks. If it hung directly overhead, then they easily got to Hawaii. And on the way back they used Sirius.
The Australians knew that with the arrival of the star Arcturus, ant larvae also came and disappeared when it aligned with the Sun in the western sky. The Vailwun tribe called her Gambila, "the red one."
In India, she was called Swati - "very useful", and among the Inuit - Uttukalualuk ("Old Man"). The modern name has been known since the time of Hesiod, when he mentioned it in 750 BC. in the poem "Works and Days".
Sometimes it is called the star of Job, because it is mentioned in the Bible (Book of Job). But there are references in fiction (D. Lindsey "Journey to Arcturus", S. Lem "Return from the Stars"), as well as films ("Aliens", "Doctor Who", "Buck Rogers").
In 1933, Arcturus was chosen to open the Chicago Fair. It was believed that her light began traveling to Earth during the previous fair (1983). Then it was believed that it was 40 light years away. But later the data was corrected to 36.7 light years.
Physical characteristics and orbit of the star Arcturus
- Arcturus is the Alpha of Bootes.
- Constellation: Bootes.
- Coordinates: 14h 15m 39.7s (right ascension), + 19° 10" 56" (declination).
- Spectral type: K1.5IIIFe-0.5.
- Distance: 36.7 light years.
- Apparent value (V): -0.04.
- Apparent value (J): -2.25.
- Absolute value: -0.30.
- Massiveness: 1.10 solar.
- Radius: 25.7 solar.
- Luminosity: 170 solar.
- Temperature mark: 4290 K.
- Rotation speed: 2.4 km/s.
- Names: Arcturus, Bootes Alpha, Bootes α, Bootes 16, HD 124897, HR 5340, HIP 69673, LHS 48, BD + 19° 2777, GCTP 3242.00, GJ 541, FK5 526, SAO 100944, LTT 14184, LFT 100944, LTT 14188, LFT 100944 , NSV 6603.
There are many beautiful stars in the sky, and one of them is the star Arcturus. This star has many advantages that only people who are seriously interested in astronomy or professionally involved in this science can properly appreciate.
The star Arcturus is the brightest star in the northern hemisphere, and in the list of the brightest stars in the night sky, it takes an honorable fourth place. If we compare the brightness of the glow of Arcturus with the glow, then the star Arcturus will be 110 times brighter than our star. If we compare the glow of Arcturus and the Sun on a bolometric scale (in the entire wavelength range, taking into account infrared radiation), then Arcturus will be brighter than the Sun by about 180 times, and its glow will be much more intense than the sun.
The extreme brightness of Arcturus is an important, but not the main advantage of this celestial body. In addition to brightness, astronomers attribute the large proper motion of this star, as well as its extragalactic origin, to the merits of Arcturus.
As for the physical parameters of the star, they are very impressive. Arcturus has a small mass, which is approximately equal to the mass of our Sun, but its radius exceeds the radius of the Sun by about 27 times. This indicates the extreme lightness of this star, caused by a low percentage of heavy metals in it.
Proper motion of Arcturus
To begin with, let's figure out what it is generally such a "proper motion of a star." The proper motion of a star is the ability of a celestial body to move in the coordinate system of the cosmic sphere per unit of time. Simply put, this is the ability of a star to change its position in the night sky.
The star Arcturus has its own motion in the coordinates of the celestial sphere is very huge. An angular distance of 30′ long Arcturus travels in just eight hundred years, which is a significant figure on a cosmic scale. The movement of Arcturus was first discovered and observed in 1917 by the great English mathematician and astronomer Edmond Halley.
Among the observed stars of the night sky, Arcturus has the highest speed of its own motion (122 km / s), yielding in this regard, perhaps, to the star
It should be noted that the star Arcturus is the most famous star that is included in the famous asterism - the Arcturus stream, which has over fifty stars connected by a common proper motion.
Arcturus flow
Observing the main star of the constellation - the star Arcturus, astronomers discovered that this cosmic body does not move independently in the celestial sphere. It is accompanied by a kind of "retinue", consisting of other, smaller stars, of which there are over 50 pieces. Scientists noticed that the magnitude and direction of their own motion for these stars is approximately the same, so they decided to combine them into one asterism, which they called the Arcturus Stream.
The stream of Arcturus, in addition to its main celestial body - the star Arcturus, has such famous stars as Nu Virgo, Alpha Chanterelles, 27 Cancer and others.
Scientists believe that these cosmic bodies, including the star Arcturus, have nothing to do with the Milky Way galaxy and are united by an extragalactic origin.
Origin of the star Arcturus
Modern studies of the star Arcturus and analysis of the spectrum of its glow indicate that this celestial body is one of the old stars with a low content of heavy metals.
As a rule, our galaxy - the Milky Way, does not have stars of a similar composition, which means that there is reason to believe that Arcturus comes from another galaxy.
The extragalactic origin of the star Arcturus is also indicated by the type and age of this star. The star Arcturus belongs to the category of orange giants of the spectral class K. The age of the star is approximately 7.1 billion years. These data indicate that the named celestial body is among the stars of population II, which are characteristic of more ancient galactic formations.
The high speed of Arcturus in outer space also leads scientists to believe that this star was formed in another galaxy, which was subsequently absorbed by the Milky Way. This fact is also indicated by the existence of the Arcturus Stream - the number of stars united by their own movement in the celestial sphere.
This movement, low metal content, and long age lead cosmologists to speculate that these stars formed in an ancient dwarf galaxy.
origin of name
Like most stars in the night sky, Arcturus has several names: Alpha Bootes, α Boo, Hokulea, Haris-as-sama and others. But the generally accepted name of this star is considered to be the name "Arcturus". This name comes from the ancient Greek language and translates roughly as "Guardian of the Bear."
According to ancient legend, the goddess Hera, angry at the nymph for making love to her husband Zeus, turned her into a bear (the constellation Ursa Major). In order to protect his beloved from further assassination attempts by a jealous wife, Zeus sent Arcade (the star Arcturus) to heaven, their common son with Callisto, in order for him to protect his mother. So it turned out that the star Arcturus is a kind of guardian, or, more simply, a satellite, of the constellation.
List of brightest stars
| № | Name | Distance, St. years | Apparent magnitude | Absolute value | Spectral class | celestial hemisphere |
|---|---|---|---|---|---|---|
| 0 | 0,0000158 | −26,72 | 4,8 | G2V | ||
| 1 | 8,6 | −1,46 | 1,4 | A1Vm | Southern | |
| 2 | 310 | −0,72 | −5,53 | A9II | Southern | |
| 3 | 4,3 | −0,27 | 4,06 | G2V+K1V | Southern | |
| 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 | Southern | |
| 8 | 11,4 | 0,38 | 2,6 | F5IV-V | Northern | |
| 9 | 69 | 0,46 | −1,3 | B3Vnp | Southern | |
| 10 | ~530 | 0.50 (variable) | −5,14 | M2Iab | Northern | |
| 11 | ~400 | 0.61 (variable) | −4,4 | B1III | Southern | |
| 12 | 16 | 0,77 | 2,3 | A7Vn | Northern | |
| 13 |
Watching UFOs is no longer a novelty for me, they fly every day, but today I saw something new and unusual. At 00:00, an object of the same color and size as the star separated from the star Arcturus, and then, with stops in 5 minutes, moved to the star Mufrid and merged with it.
It contains a large number of chemical elements that are larger than hydrogen in mass. The iron/hydrogen ratio is believed to reach an upper limit for dwarf stars. Mufrid is a spectroscopic binary star with a period of 494 days.
In the starry sky? Bootes is located near Arcturus (? Bootes) and, indeed, Arcturus is Mufrid's closest stellar neighbor, both stars are located almost at the same distance from the Sun (approximately 37 light years). The distance between the stars is 3.24 light years. If Arcturus is observed from Mufrid, its apparent magnitude will be -5.2.
The distance between the stars is 3.24 light years and this object has overcome it in just 5 minutes.
Visually, both stars of white-blue radiance, the same color was the object that separated from Arcturus, and visually the same size, although as it approached Mufrid, it decreased to its size and then simply merged with him.
The name of the star comes from the ancient Greek ????????? ( Arcturus), "Guardian of the Bear". According to one version of the ancient Greek legend, Arcturus is identified with Arkad, who was placed in the sky by Zeus to protect his mother, the nymph Callisto, who was turned by Hera into a bear (the constellation Ursa Major). According to another version, Arkad is the constellation of Bootes, the brightest star of which is Arcturus.
Arcturus is called in Arabic Haris-as-sama", "guardian of the heavens". (see Haris)
In Hawaiian, Arcturus is called Hokulea (gav. Hokule’a) - “star of happiness”, in the Hawaiian Islands it culminates almost exactly at the zenith. Ancient Hawaiian navigators relied on its height when they sailed to Hawaii.
Arcturus holds many mysteries. Presumably, Arcturus may be a double star, but this has not yet been proven. Attempts to find a planet revolving around a star have so far been unsuccessful, although this is quite within the technical capabilities of mankind.
If in his youth Arcturus possessed some planets, like the Earth, then he burned them a long time ago. And now, in order to have the earth's temperature, the planet must be at a distance of 11 astronomical units (distances from the Earth to the Sun). It is somewhere in the region of our Uranus.
This is what Arcturus looks like from an imaginary planet
The ancients believed Bootes one of the most important constellations; Sumerians the Greeks called it "the constellation of the faithful heavenly shepherd", the Greeks - the "ox driver" and "bear guard". Arcturus - the first star in which Edmond Halley discovered back in 1718 clear movement in space. Proper motion of Arcturus very large, more than any other first magnitude star except for? Centauri. An angular distance of 30? (apparent diameter of the Moon) Arcturus passed in about 800 years. Arcturus was the first star to be seen during the day with a telescope. This was done in 1635 by the French astronomer and astrologer Morin.
. “To be born under a lucky star” is given to a few, and if this happened, and at the birth of a child, one or another star rose, or was at its zenith, then it can greatly affect a person’s life - sometimes, under certain conditions, even stronger than the horoscope itself birth (location of stars and planets).
Each star has its own characteristic of influence. For example, a star Arcturus, which can now be observed in the west in constellation Bootes, are credited with great magical power, good luck, but also great responsibility. She does not allow cowardice: as soon as a person is afraid, all misfortunes will fall on him and retribution for apostasy will come immediately.
In order to better understand the meaning of a star, to feel its spirit, let us consider astronomical and mythological knowledge about this beautiful and unusual cosmic object - after all, it is the synthesis of contradictory at first glance knowledge and facts that helps to look beyond the veil of truth.
The name of the star comes from the ancient Greek Arcturus. According to one version of the ancient Greek legend, Arcturus is identified with arcade, which was placed in the sky by Zeus to guard his mother - the nymph Callisto, who was turned by Hera into a bear (the constellation Ursa Major).
According to another version Arkad- it constellation Bootes, whose brightest star is Arcturus. In Arabic, Arcturus is called Haris-as-sama. "guardian of heaven". In Chinese astronomy, Arcturus is called Da Jiao ("great horn"). In Indian astrology, or Vedic astrology, Arcturus is called Swati, derived from the Sanskrit word.
Star Swati considered in Indian astronomy as the fifteenth zodiac constellation, which tradition considers especially auspicious. There is a belief that people born under the star of Swati are always happy, beautiful and loved.
So, Arcturus- Alpha of the constellation "Boötes", which rushes across the starry sky with great speed. This was first noticed back in 1718 by Edmund Halley. Its luminosity is more than a hundred times greater than that of the sun. That is why Arcturus, the distance to which is 36.7 St. years, one of the brightest stars in the sky.
Arcturus is a fleeting guest in the family of our constellations. This giant appeared in our sky only half a million years ago. Early Neanderthals saw it as an ordinary star in the constellation Draco, and in twenty thousand years Arcturus will already “get a residence permit” in the zodiac sign Virgo. In another half a million years, it will be out of sight forever.
Here is a quote from a book about the life of Edgar Cayce "River of Life": "One day, when Morton found out that Arcturus is a stopping place for souls leaving solar system, and that on this star the soul chooses for itself the next life experience, he asked at what stage in its development the soul can reach this star. "You can't talk about it," was the answer.
And one more interesting fact: Vladimir Putin Arcturus has some aspects with his personal planets, but hidden in the shadows. "Guardian of the Bears" and here he expresses himself with his own strength: he symbolizes the sentry guarding his territory. This is a transitional figure between the hunter-gatherer and the farmer.
Arcturus symbolizes protection, training and leadership at the same time. To whom much is given, much is asked: such people are always responsible for the fate of other people and they are obliged to protect and take care of them.
In principle, Arcturus can be considered an evil star, but in fact he is neither evil nor kind, but gives great strength, and hence the danger of being crushed by this force. Arcturus sets a task for a person to go to the end in any business, otherwise he will be crushed.
At a higher level, Arcturus allows you to accept and assimilate very distant traditions and teachings. Astrologers also believe that a person with Arcturus turned on at some point in his life will definitely turn to religion, become a deeply religious person.
So far, in the Putin couple, only one person has turned to religion, and this is not Putin, but his ex-wife, Lyudmila Putina. Why did their paths diverge? About this and about the promised continuation of the topic of
What do you associate spring with? Everyone probably has some kind of association: for some, the first thing that comes to mind is the return of long days and the retreat of the night, for some there are snowdrops in the thaw, and someone remembers the first truly warm day. The author of this article has his own association associated with spring - a bright star Arcturus, which reigns in the evening sky in mid-April and then is clearly visible until early autumn. All the delights of spring pass under the shadow of this star - both long evenings, and warm winds with the smell of thawed earth, and the appearance of the first leaves on the trees ...
At the end of March, when spring has just begun according to the astronomical calendar, Arcturus is not yet the sovereign master of the night sky. Nevertheless, it will be useful to find it for those who are just starting to get acquainted with the starry sky. Why? Read on.
First, let's see where Arcturus is in the March sky after dusk. An hour after sunset, this star can be found in the northwest, low on the horizon. You will recognize it by its great brightness (Arcturus is one of the brightest stars in the sky) and by the strong twinkling characteristic of all bright stars located near the horizon.
After dusk in March, Arcturus is visible low on the horizon in the northeast. A good pointer to it is the handle of the Big Dipper bucket. Arcturus has a distinct orange color, but near the horizon it can shimmer with all the colors of the rainbow if the atmosphere is turbulent. Drawing: Stellarium
A good pointer to Arcturus is the bucket of Ursa Major. Just be careful: in the evenings in March, the bucket is in an unusual position: it seems to be standing on the handle, pointing with the bucket itself to the zenith, and with the handle to the horizon. If you mentally extend the line connecting the last two stars of the bucket handle to the horizon, then it will pass not far from Arcturus.
In the future, when Arcturus rises higher in the sky, the need to search for him will disappear. Arcturus is so bright that only the Moon and planets can be its rival in the March night sky (Jupiter is such a planet in 2016).
When is this time? When is Arcturus visible high up in March? If you observe in a big city, then starting from ten or eleven o'clock in the evening, the star rises over neighboring houses, and at midnight is visible about halfway between the horizon and the zenith in the southeast. On March nights, Arcturus shines high in the sky in the south, and in the morning disappears against the brightening sky in the southwest.
In the second half of March, Arcturus is high in the southeast at midnight. In 2016, to the right of the star are Jupiter and the Moon, which are much brighter than it. But among the stars, Arcturus has no rivals at this time. Drawing: Stellarium
If you get a chance, look at the late March sky after midnight. At this time, the remnants of the bright winter constellations set in the west. The southern and eastern sky is dark and empty. Only three bright stars are in this vast sector: (alpha of the constellation Leo), spica(Virgo alpha) and Arcturus, the main star of the constellation Bootes. Orange Arcturus is brighter than the other two stars, so it can (and should!) be used as one of the landmarks for finding dim spring constellations. The Serpent and Bootes, the Northern Crown and the Hair of Veronica, Libra and the Hounds of the Dogs - all these unimpressive constellations can be easily found if you start from Arcturus. That is why it is necessary to know the location of this wonderful star. (And it is really remarkable - Arcturus is one of the giant stars closest to the Earth - its diameter is 26 times the diameter of the Sun!)
Comparison of the sizes of the Sun and some bright stars. The diameter of Arcturus exceeds the solar one by 26 times. Drawing: Big Universe
But if you prefer to sleep at night, then do not be upset: in April and May, the heavenly picture will change. The Earth will make an impressive journey in its orbit around the Sun, and those stars that were visible in the evening in the east in March will shift 30-60 ° to the west. The winter constellations will finally set, and Arcturus will no longer hide at the horizon with the onset of twilight - it will flare up high in the sky in the southeast, to then reign in the sky all night.
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