For the convenience of navigating 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 Claudius Ptolemy created his catalog. Among them is the constellation Bootes, which in ancient Greece was also called Arctophylax (translated as “guardian 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 Big Dipper for a start: the constellation Bootes is located to the left of the ladle handle. The celestial drawing is familiar to many by its most noticeable point - Arcturus. This star is the fourth brightest, after Sirius, Canopus and Alpha Centauri.
Orange Giant
Arcturus is not only the brightest star in the constellation Bootes, it is the leader in this parameter in the entire northern hemisphere. On the territory of our country, it is especially noticeable in the spring. Until the middle of summer, Arcturus is located quite high above the horizon in the southern part of the sky. In autumn, it moves to the west, closer to the horizon.
The brightest star in the constellation Bootes is an orange giant, 110 times brighter than the Sun. Due to the constant pulsation of the surface of the star, its brightness changes by 0.04 magnitude every eight days with a little. Such properties make it possible to attribute Arcturus to the class of variable stars.
Guest from another galaxy
Arcturus is thought to be a little over seven billion years old. It is one of the stars that make up the so-called Arcturus stream, 52 luminaries moving at almost the same speed in the same direction. Some parameters of these cosmic bodies lead scientists to the conclusion that once upon a time they were part of another galaxy, swallowed up by the Milky Way. It turns out that an observer studying Arcturus from Earth sees one of the oldest stars and an alien from another galactic system at the same time.
Tales of the Ancients
One of the myths connected with Arcturus explains how the constellation Bootes appeared. Legend has it that Arkad, his son, was turned into a star by Zeus in order to save him from imminent death. In different versions, the hero was placed in the sky either as a specific star or as an entire constellation. His mother was Callisto, a servant of the goddess Artemis or daughter of King Lycaon. Zeus, wanting to save his beloved from angry revengewife, 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 as an excellent hunter and, not recognizing his mother in the beast, almost shot her. The released arrow was taken away by Zeus. After that, 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, Arctophylax, comes from the same legend: Arkad constantly guards the she-bear in the sky, holding the Big Dogs and protecting her from other misfortunes.
The Boötes constellation for children may be interesting just like its connection with neighboring celestial drawings. The legend makes it easier to remember the location of several figures at once.
Binary Systems
The Boötes constellation diagram includes 149 stars visible to the naked eye, and Arcturus is not the only object worthy of attention among them. Isar (epsilon), Mufrid (eta) and Seginus (gamma) also stand out in brightness. And they are all double stars.
Izar or Itzar (Arabic for "loincloth") is a system that includes a bright orange giant and a white main sequence star. The distance between them is 185 astronomical units, and the period of revolution exceeds a thousand years.
Mufrid is a close neighbor of Arcturus (a diagram of the constellation Bootes is shown below). One of the components of this system is similar in color and surface temperature to the Sun, but does not belong to the yellow giants. The life stage he overcomes is characterized as intermediate on the way to turning into a redgiant. His companion is less impressive in his parameters. It is a red dwarf main sequence object.
Seginus is located on the shoulder of Bootes and also consists of two luminaries. Refers to Delta Scuti type variable stars that have a brightness that changes every few hours due to surface pulsations.
Zeta
The constellation Bootes also boasts the presence of triple stars. Zeta is one of them. Its first two components (A and B) are almost identical in magnitude. The luminosity of each is 38 times greater than that of the Sun. At the same time, the Zeta Boötes star system is a rather dim cosmic object and, perhaps, therefore, has no other historical name.
The third component is still one of the mysteries of the universe. All that is known about it is that it revolves around the named pair, as it always happens in triple systems, and has a magnitude of +10, 9.
44 Bootes
There is another interesting triple object in the constellation. These are 44 Bootes. A close pair in the system consists of two stars so close to each other that their surfaces touch. 44 Bootes B and 44 Bootes C revolve around each other in just three hours, the distance between them is just over a million kilometers. For space, such values are negligible. The stars are constantly exchanging material and form an unstable system, often generating huge explosions.
Component B of the system is similar in mass to the Sun, its radius is also close to the corresponding parameter of our star. Belongs to the class G2 V. 44 Bootes C has been studied rather poorly. It is inferior in luminosity and mass to component B, and in diameter it is 40% smaller than the Sun. Belongs to the class of yellow dwarfs.
44 Bootes A is in many ways similar to our star. Its radius and luminosity practically coincide with the corresponding parameters of the Sun. The distance from this component of the triple system to a pair of aircraft is constantly changing, since the orbit of motion has the shape of an elongated oval. On average, its magnitude is 48.5 astronomical units.
Satellites of our galaxy
Boötes is also notable for one more object located on its "territory". In 2006, a dwarf galaxy, also named Bootes, was discovered here. Such systems are among the satellites of the Milky Way, being in a gravitational relationship with it, similar to the connection between the Earth and the Moon. Bootes (constellation), which was photographed 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 image. The discovery of such galaxies plays an important role in refining the theory of the formation of the Milky Way and the entire Universe.
Boötes, a beautiful and noticeable constellation, still holds many secrets and is in no hurry to reveal them to curious astronomers. Not all of its stars have been studied. Periodically flash messages about new objects discoverednear Bootes. We can safely hope that this constellation, like all deep space, will give us many more discoveries.
