For the convenience of orienting on the terrain, as well as studying the sky, all the stars from ancient times were divided into groups that form the silhouette of certain objects or mythical characters. Over time, the nature of some groups changed, their number increased. However, most of the constellations retained their names and configuration as they were in the second century AD, when he created his catalog of Claudius Ptolemy. Among them is the constellation Bootes, which in ancient Greece was also called Arctofilax (translated as “the guard of the bear”).
Location in the sky
Bootes in the northern hemisphere can be observed all summer. Finding it is easy. It is enough to find the Ursa Major for starters : the constellation Bootes is located to the left of the bucket handle. Heavenly drawing is familiar to many by its most noticeable point - Arcturus. This star is the fourth brightest, following Sirius, Canopus and Alpha Centauri.
Orange giant
Arcturus is not only the brightest star in the constellation Bootes, it leads in this parameter throughout the northern hemisphere. On the territory of our country, it is especially clearly visible in the spring. Until mid-summer, Arcturus is located quite high above the horizon in the southern part of the sky. In the autumn, it moves west, closer to the horizon.
The brightest star in the constellation Bootes is an orange giant, luminosity exceeding the Sun by 110 times. Due to the constant pulsation of the surface of a star, its luminosity changes by 0.04 magnitude every eight days. Such properties allow us to attribute Arcturus to the class of variable stars.
Guest from another galaxy
Arcturus is estimated to be a little over seven billion years old. It belongs to the number of stars that make up the so-called stream of Arcturus, 52 luminaries moving at almost the same speed in one direction. Some parameters of these cosmic bodies lead scientists to the conclusion that once upon a time they were part of another galaxy absorbed by the Milky Way. It turns out that an observer studying Arcturus from Earth sees at the same time one of the oldest stars and an alien from another galactic system.
Tales of the Ancients
Associated with Arcturus is one of the myths explaining how the constellation Bootes appeared. Legend has it that Arkad, his son, was turned into a star by Zeus for the sake of salvation from imminent death. In different versions, the hero was placed in the sky either as a specific star, or as the whole constellation. His mother was Callisto, a servant of the goddess Artemis or the daughter of King Lycaon. Zeus, wanting to save her beloved from the revenge of her angry wife, Hera, according to another version, from Artemis herself, to whom all her servants took a vow of celibacy, turned Callisto into a bear. Arkad grew up an excellent hunter and, not recognizing his mother in the beast, he nearly shot her. The released arrow was diverted by Zeus. After which he decided to permanently save Callisto and Arcade from persecution, turning the hero into the constellation Bootes, and his mother into the Big Dipper. The second name of the star pattern, Arctofilax, hails from the same legend: Arcade in the sky constantly guards the she-bear, holding the Big Dogs and protecting her from other misfortunes.
The Bootes constellation for children can be interesting just by its similar connection with neighboring celestial drawings. The legend makes it easy to remember the location of several figures at once.
Dual systems
The Bootes constellation scheme includes 149 stars visible with the naked eye, and Arcturus is not the only object worthy of attention among them. In terms of brightness, Isar (epsilon), Moufrid (this) and Seginus (gamma) are also distinguished. Moreover, they are all double stars.
Isar or Itzar (from the Arabic “loincloth”) - a system that includes a bright orange giant and a white star of the main sequence. The distance between them is 185 astronomical units, and the period of revolution exceeds a thousand years.
Moufried is a close neighbor of Arcturus (the scheme of the constellation Bootes is given below). One of the components of this system with color and surface temperature is similar to the Sun, but does not apply to the yellow giants. The life stage he overcomes is characterized as intermediate on the way to becoming a red giant. His companion is less impressive in its parameters. This is a red dwarf related to objects of the main sequence.
The seginus is located on the Bootes shoulder and also consists of two luminaries. Refers to Shield Delta type variable stars with a luster that changes every few hours due to surface pulsation.
Zeta
The constellation Bootes boasts the presence of triple stars. These include Zeta. Its first two components (A and B) are almost identical in magnitude. The luminosity of each is 38 times greater than a similar parameter of the Sun. At the same time, the stellar system of Zeta Bootes is a rather dim cosmic object and, perhaps, therefore, has no other historical name.
The third component is still one of the secrets of the universe. What is known about him is that he rotates around the named pair, as is always the case in triple systems, and has a magnitude of +10.9.
44 Bootes
There is another interesting triple object in the constellation. This is 44 Bootes. The close pair in the system consists of two stars so close to each other that their surfaces are in contact. 44 Bootes B and 44 Bootes B revolve around each other in just three hours, the distance between them is just over a million kilometers. For space, such values are negligible. Stars constantly exchange material and constitute an unstable system, often generating powerful explosions.
The B component of the system is similar in mass to the Sun, its radius is also close to the corresponding parameter of our luminary. Belongs to class G2 V. 44 Bootes C is studied quite poorly. It is inferior in luminosity and mass to component B, and in diameter less than the Sun by 40%. Belongs to the class of yellow dwarfs.
44 Bootes And in many ways is similar to our star. Its radius and luminosity practically coincide with the corresponding parameters of the Sun. The distance from this component of the ternary system to the aircraft pair is constantly changing, since the orbit of movement has the shape of an elongated oval. On average, its value is 48.5 astronomical units.
Satellites of our galaxy
Bootes is also noteworthy for another object located on its "territory". In 2006, there was discovered a dwarf galaxy, also called Bootes. Similar systems are among the satellites of the Milky Way, being with him in gravitational relationships, such as the connection of the Earth and the Moon. Bootes (constellation), whose photo was taken more than once by telescopes, was identified as the owner of a dwarf galaxy through careful calculations and calculations. Such a dim space object cannot be captured in any picture. The discovery of such galaxies plays an important role in refining the theory of the formation of the Milky Way and the entire Universe.
Bootes, a beautiful and conspicuous constellation, still has many secrets and is in no hurry to reveal them to curious astronomers. Not all of his stars are studied. From time to time, messages about new objects discovered near Bootes flicker. We can safely hope that this constellation, like the whole deep space, will give us many more discoveries.