Constellation Lyra - a small constellation of the northern hemisphere. Star of Vega in the constellation of Lear

In summer, the sky in cloudless nights is especially beautiful. It seems that the number of flickering points overhead after the winter has multiplied. In the northern hemisphere, almost in the middle of the celestial dome, you can see a fairly bright star just above the crown of the observer. This is the Vega, Alpha constellation of Lyra, a small heavenly figure, located in such a favorable place from the last days of spring and the middle of autumn. The image of an ancient musical instrument, despite its modest size compared with its neighbors, has long attracted the attention of astronomers.

Environment and shape

The constellation of Lear contains 54 luminaries visible from the Earth with the naked eye. Its closest neighbors in the sky are Swan, Hercules, Dragon and Chanterelle. Find the brightest point of the picture, Vega, is quite simple not only due to its position. Alpha Lyra - one of the tops of asterism Summer triangle, consisting entirely of very bright and well-marked stars. The other two corners of it are denoted by Deneb from the constellation Cygnus and Altair, referring to the heavenly image of the Eagle.

In form, the constellation of Lyra resembles a quadrangle, all of whose peaks are clearly visible on a clear night. A short distance from one of them is Vega.

Constellation Lyra: a legend

As you know, this heavenly figure bears the name of an ancient musical instrument. In ancient Greece, the lyres made turtle shells. In honor of the animals, the instrument was named: the word "lyre" in translation means "tortoise". According to legend, the first such thing, capable of making melodic sounds, gave people Hermes. Lira always accompanied the mythical singer Orpheus. According to legend, his music and voice captivated both gods and people. There, where the sounds of the lyre were heard, the flowers blossomed and the birds sang. Orpheus had a difficult fate: he lost his wife, Eurydice, descended into the realm of the dead, tried to return, but at the last moment broke one of the main conditions of Hades. Having lost his beloved, Orpheus threw out the lyre and left in silence and sorrow to live out his age. The gods, reverent before the sounds of the instrument, carried it to heaven and made it a constellation.

Lovers

The star of Vega is associated with a separate legend, having an eastern origin. Japanese and Chinese mythology correlates it with the beautiful goddess who fell in love with a mortal. A young man is also placed on the sky: this is Altair from the constellation Eagle. The father of the goddess, who knew about the secret love, became angry and forbade his daughter to meet with the chosen one. Since then, Vega and Altair are separated by a celestial river, the Milky Way. Lovers are given to meet only once a year, the seventh of July, when thousands of forty build a bridge between them. After the night the goddess comes back and bitter tears mourns separation. Salty drops are seen from Earth as falling meteors, Perseids.

Alpha

The brightest star in the constellation of Lear from ancient times attracted not only the eyes of storytellers. She was always interested in scientists. The unique position of the light and its visibility led to the fact that today Vega - one of the most studied stars in space.

By brightness, it occupies the fifth place in the whole sky and the second in the northern hemisphere after Arcturus. The apparent magnitude of Vega is 0.03. It refers to objects of the spectral class A0Va, its mass exceeds solar 2.1 times, and diameter - 2.3.

The Future of the Sun

Star Vega is a white and blue giant. According to scientists, it has been shining for 455 thousand years. For a person this is an astounding figure, but by the standards of the universe, Vega does not live long. For comparison, the Sun illuminates our site of the Galaxy for 4.5 billion years. The intensity of radiation and other characteristics will not allow the main star of Lyra to exist for a long time. Astronomers predict Vega fading and destruction after about 450 thousand more years.

Standard

Due to its position, Vega is well studied, which, in turn, served as its confirmation in the role of a certain standard in astronomy. From the middle of the 19th century, its magnitude determined the magnitude of several hundred luminaries. Vega became one of seven stars located at such a distance from the Sun that cosmic dust does not distort the radiation coming from them, on the basis of which the photometric system UBV, which allows determining certain physical parameters of the luminaries, was perfected.

Despite the seemingly comprehensive study of Vega, there are a number of issues related to it, which have not yet received exhaustive answers. One of them undermines the "reputation" of Alpha Alpha as a standard in astronomy. In the last century, there were "malfunctions" in the brilliance of the star. The received data testified that he hesitates. In this case, Vega is attributed to variable stars. There is no unequivocal opinion on this matter.

Rotation

In the sixties of the 20th century, the usual definition of the spectral class of Vega was also in doubt. It turned out that alpha Lyra is too hot and bright for standard representatives of her type. The fact did not receive a worthy explanation until 2005, when the solution was found.

It turned out that Vega rotates around its axis at a high speed (the indicator reaches 274 km / s near the equator). Under such conditions, the shape of the cosmic object changes. Vega is not a more or less regular ball, but an ellipse, elongated along the equator and oblate at the poles. As a result, contrary to the custom, the northern and southern outskirts of the star are located closer to the hot nucleus than the equatorial zone. The poles warm up more brightly.

This hypothesis arose in the 80 years of the last century and was confirmed by observations in 2005. It explains both the anomalous luminosity of the star, and its brightness.

Disk

Vega is characterized by one more feature: it has a circumstellar dust disk. She was the first luminary to have found such a formation. A disk consists of the remains of cosmic objects colliding with each other near the star.

The discovery of the disc was preceded by the discovery of an excess of infrared radiation from Vega. Today, all the luminaries with this characteristic are designated as "Vega-like".

Some features in the structure of the dust disk suggest that around the alpha of Lyra revolves a huge planet, similar to Jupiter. While this data is not confirmed, however, if this happens, Vega will become the first brightest star with a planet.

Sheliak

Among the interesting objects of the heavenly musical instrument is not only Vega. The constellation of Lyra has several multiple star systems. The attention of scientists is primarily attracted to Sheliac, Beta Lyra. It refers to eclipsing variable lights. The system consists of a bright white-blue dwarf and a large, but more dim white star, belonging to the main sequence. They are separated by 40 million kilometers, which is very small by space standards. As a result, the substance from one of the companions continuously flows to the other.

The gas moving from the "donor" forms an accretion disk around the "recipient". At the same time, both stars are surrounded by a common gas shell, constantly giving part of its substance to the surrounding space.

Originally the mass ratio of the companions looked different. Today's donor was more impressive. Over time, he turned into a giant and began to give away his substance. Now its mass is estimated at 3 solar, whereas this parameter in the companion is equal to 13 masses of our luminary.

At some distance from the main pair is the third star, beta Lira B. By brightness, it is 80 times greater than the Sun. Beta Lira B refers to the spectroscopic double (period is - 4.34 days).

Epsilon

The constellation of Lear has also a star system consisting of four components. This epsilon Lyra, divided into two components Epsilon 1 and Epsilon 2, even when viewed with binoculars. Each of them is a pair of luminaries. All four components are 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

Virtually any heavenly figure can boast of beautiful nebulae in its "territory". The Lyre constellation is no exception. The photo of the space object, located between the gamma and beta Lira, gives a clear idea of the origin of its name. The Ring Nebula in its form, indeed, resembles the corresponding piece of jewelry. It adorns the constellation of Lear, located at a distance of 2,000 light years from Earth. The age of the nebula is estimated at 5.5 thousand years. You can see it with binoculars. The beautiful glow of the nebula is due to the ultraviolet radiation emitted by the white dwarf. Once it was the core of a massive star.

Near the nebula there is a globular star cluster M56. Their neighbors, however, are imaginary: the M56 is 32.9 thousand light-years away from the Earth. In the images, it resembles a sphere, compacted to the middle, where the number of stars per unit of space is quite high. There are approximately 12 variable stars. The globular cluster is difficult to observe with the help of amateur equipment, as it is lost on the background of the Milky Way.

Lyra - the constellation is small, but nevertheless interesting. Representatives of very many objects from among those studying astronomy are placed on its "territory". The stars and constellations surrounding Lira may seem more impressive and worthy of attention. On the other hand, Vega alone has enough to "eclipse" them all. Especially if we recall that the stellar magnitudes of these stars, it is quite possible, were determined on the basis of data on Alpha Lyra. This heavenly figure, thus, is a graphic illustration of the saying "small and daring". However, the same can be said about his legendary prototype, the lyre of Orpheus.