summer sky cloudless night is especially beautiful.It seems that the number of twinkling dots above his head after the winter has increased many times.In the northern hemisphere is almost in the middle of the heavenly dome directly over the top of the observer can be seen pretty bright star.It is Vega, the alpha constellation of Lyra, a small celestial figure, is located in such an area with the last days of spring and mid-autumn.Image of ancient musical instrument, despite its modest size compared with its neighbors, has long attracted the eyes of astronomers.
Setting and shape
constellation Lyra contains 54 light, visible from Earth with the naked eye.Its closest neighbors are in the sky Swan, Hercules, Dragon and Chanterelle.Find the brightest point of the figure, Vega, quite simply, not only because of its location.Alpha Lyrae - one of vertex asterism Summer Triangle, consisting entirely of very bright and well visible stars.Two other corner of his designated Deneb in the constellation Cygnus, and Altair, referring to the heavenly eagle.
The shape of the constellation Lyra resembles a quadrangle vertices which are clearly visible on a clear night.At a short distance from one of them is Vega.
constellation Lyra Legend
As you know, this heavenly figure bears the name of the ancient musical instrument.In ancient Greece, the lyre made from the shells of turtles.In honor of the animal and call the tool: the word "lyre" means "turtle".According to legend, the first such object may emit melodious sounds, I gave people Hermes.Lear always accompanied by the mythical singer Orpheus.According to legend, his music and his voice captivated gods and humans.Where the sounds of the lyre, the flowers bloom and the birds were singing.At Orpheus was difficult fate: he lost his wife, Eurydice, went after her in the realm of the dead, tried to return, but at the last moment had violated one of the main conditions of Hades.Having lost his beloved, Orpheus threw lyre and left in silence and sorrow live out their lives.Gods blagogovevshie before the sound of the instrument, raised him to the heavens and made a constellation.
Lovers
star Vega is associated with a separate legend, has Eastern origin.The Japanese and Chinese mythology relates it with the beautiful goddess, fell in love with a mortal.The young man also placed on the sky is Altair in the constellation Eagle.The father of the goddess, found out about the secret love, angry and forbade her daughter to meet with the elect.Since then, Vega and Altair shares the celestial river, the Milky Way.Lovers given to meet only once a year, the seventh of July, when thousands forty build a bridge between them.At the end of the night the goddess returned and bitter tears mourning the separation.Saline drops are seen falling to Earth as meteors Perseids.
Alpha
The brightest star in the constellation Lyra has long attracted the eyes of not only the narrators.She has always been interested scientists.The unique position of the light and visibility led to that today Vega - one of the most studied stars in space.
bright it ranks fifth in the whole sky, and the second in the northern hemisphere, after Arcturus.The apparent magnitude of Vega - 0.03.It refers to the objects of spectral type A0Va, its mass is greater than 2.1 times the sun, and the diameter - 2.3.
future shines
star Vega - blue-white giant.According to scientists, it shines already 455,000 years.For a man this figure is striking, however, by the standards of the universe Vega does not live too long.For comparison, the sun illuminates our site Galaxy had 4.5 billion years.The radiation intensity and other characteristics do not allow the main star of Lyra also exist for a long time.Astronomers predict Vega extinction and destruction even after approximately 450,000 years.
Standard
Due to its location Vega is well understood that, in turn, served as its approval as a certain standard in astronomy.Since the mid-19th century for its brilliance it was determined magnitudes of several hundred stars.Vega was one of seven stars located at a distance from the Sun, cosmic dust that does not distort the radiation coming from them, on the basis of which was perfected photometric system UBV, which allows to determine some of the physical parameters of light.
Despite the seemingly comprehensive study of Vega, a number of related issues, to date, not received satisfactory answers.One undermines the "reputation" of the Alpha Lyrae as the standard in astronomy.In the last century it has been found "problems" in the glare of the star.The data showed that it varies.In this case, Vega is attributed to the variable stars.There is no single opinion on this matter yet.
Rotation
In the 60s of the 20th century and got questioned the usual definition of spectral type Vega.It turned out that Alpha Lyrae is too hot and bright for standard members of their type.The fact did not get a decent explanation until 2005, when the solution has been found.
It turned out that a high speed Vega rotates on its axis (near the equator figure reaches 274 km / s).In such circumstances, it changes the shape of the space object.Vega is not more or less the right ball, but an ellipse elongated along the equator and flattened at the poles.As a result, contrary to the usual northern and southern outskirts of the stars are closer to the red-hot core, than the equatorial zone.The poles are heated strongly, brighter the light.
This hypothesis originated in the 80s of the last century and has been confirmed by observations in 2005.It also explains the anomalous luminosity of the star and its brightness.
disc
Vega is characterized by another feature: it has a circumstellar dust disk.It was the first star, which had found a similar formation.It consists of the remnants of disk space objects colliding with each other in the vicinity of the star.
opening drive was preceded by the discovery of excess infrared radiation Vega.Today, all the light with such a characteristic referred to as "vegapodobnye."
Some features in the structure of the dust disc suggest that Alpha Lyrae revolves around the huge planet like Jupiter.While this data is not confirmed, but if it happens, will be the first Vega, the brightest star that has a planet.
Sheliak
Among interest heavenly musical instrument is not only Vega.Lyra has several multiple star systems.The attention of scientists primarily attracts Sheliak, Beta Lyrae.It belongs to the eclipsing variable luminaries.The system consists of a bright blue-white dwarf and a large, but a dim white star belonging to the main sequence.They shared the 40 million kilometers, that cosmic standards, very little.As a result, material from one of the partners continuously flows to the other.
moves from "donor" gas forms around the "recipient" accretion disk.At the same time both stars are surrounded by a common gaseous envelope, constantly gives a part of its substance into the environment.
Initially, the weight ratio of companions looked different.Today's donor was more impressive.Over time, it turned into a giant, and began to give her stuff.Now his weight is estimated at 3 sun, while this parameter is equal to 13 companion at the mass of our sun.
at some distance from the main couple is the third star, Beta Lyrae V. bright it 80 times greater than the sun.Beta Lyrae B refers to a spectroscopic double (the period is - 4.34 days).
Epsilon
constellation Lyra possesses the star system consisting of four components.It epsilon Lyrae is divided into two components Epsilon Epsilon 1 and 2, even when observing with binoculars.Each of them is a pair of stars.All four components - white stars belonging to the same spectral class as Sirius.Epsilon 1 and 2 rotate with a period of 244 thousand years.
ring and ball
Almost every heavenly picture boasts beautiful nebulae in their "territory".No exception and the constellation Lyra.Photos of the space object located between the beta and gamma Lyrae, gives a clear idea of the origin of its name.Ring Nebula its form, indeed, resembles the appropriate piece of jewelry.She decorates the constellation Lyra, lying at a distance of 2000 light years from Earth.Age nebula is assumed to be 5500 years.You can see it through binoculars.The beautiful glow of the nebula is due to ultraviolet radiation emitted by a white dwarf.Once it was the core of a massive star.
far from the nebula is located globular cluster M56.The proximity of them, however, alleged: M56 removed from Earth at 32,900 light years.In the pictures it looks like the ball, sealed to the middle, where the number of stars per unit area is quite high.Here are placed about 12 variable stars.A globular cluster is difficult to observe using amateur equipment, as it lost against the background of the Milky Way.
Lear - a constellation of small, but nonetheless interesting.In its "territory" placed the representatives of so many objects from among those studying astronomy.Stars and constellations surrounding Lear may seem more impressive and worthy of attention.On the other hand, alone Vega bright enough to 'overshadow' all of them.Especially if we remember that the magnitudes of these stars, it is possible, determined on the basis of data on alpha Lyra.This heavenly figure, so - a graphic illustration of the saying "small but perfectly formed."However, the same can be said about his legendary prototype, the lyre of Orpheus.
