Altair is the star, the hero of legends and the object of research

To the naked eye, only a small part of the stars that fill the universe is available for observation. However, they are enough to appreciate all the greatness of the cosmos. In the list of the most notable luminaries in the twelfth place is Altair, a star that often occupies the minds of astronomers.

Location:

To find a luminary is simple enough not only because of its brightness. The star Altair is located in the constellation Eagle, occupying an impressive section of the sky and generally well visible. The name of the luminary clearly indicates its belonging. It is formed from "al-Nash al-Tair", which in Arabic means "flying eagle".

The ideal time for observing the heavenly pattern is from June to August. Eagle refers to the equatorial constellations, and therefore is better seen in the central and southern regions of our country, although in the northern regions it is available for study. This heavenly figure lies to the south-west of Cygnus. To learn the Eagle easily on the three stars, which constitute an almost ideal straight line. They are Altair, Tarazed and Alshain. Also astronomers unite them in asterism.

The hero of the legend

Altair is a star that does not enter into one asterism. The most famous combination of luminaries with his participation is the Summer Triangle. "Companions" of Altair in it are Vega (constellation of Lear) and Deneb (constellation Cygnus). All the luminaries that make up the asterism are clearly visible. Since antiquity, they have been participants in a variety of legends. In one of them Altair appears as a shepherd, who once a year, on the night of Ivan Kupala, meets his beloved Vega, a weaver.

Options

It is not difficult to guess that in the heavenly figure of the Eagle the brightest star is Altair (alpha constellation). This luminary spectral class A is not much ahead of the Sun in its size. The weight of Altair is 1.7 times larger than its analogous parameter, approximately in the same ratio are the diameters of two celestial bodies. The brightness of the Eagle's Alpha is largely the result of its relatively close location to the Earth. Altair from the Sun is about 16.8 light-years away. In addition, the alpha Eagle is brighter than our star. Altair's luminosity is nine times the solar brightness.

Fast

Altair is a star not only known for its brightness and visibility. It is characterized by a very rapid rotation around its axis. One turn makes a star for a period of 6 to 10 hours (in different sources, the information is somewhat different). To appreciate this speed, if you recall that the sun requires much more time for this - 25 days.

Such speed has its consequences. Altair is a star having the shape of an ellipse. Rapid rotation led to compression of the luminary near the poles. As a result, the diameter of the star at the equator is 22% greater than the polar diameter. Originally oblate form Altair was discovered during the theoretical calculations, but in 2007 scientists received evidence of the correctness of these constructions.

Difficulties

Specialists of the Center for High-Resolution Astronomy at the University of Georgia, under the leadership of John Monier, chose Altair as an object for study. It was supposed to take a picture of the surface of the luminary. The formed image would be the first to show so close a star outside the solar system. However, in order to obtain similar photographs of a light of the size of Altair, located at the same distance, a telescope with a mirror of three hundred meters in diameter is needed. For modern level of technology development such equipment is a matter of the future.

The obvious problem did not stop the scientists. Four telescopes arranged in a circle with a diameter of 250 m were used for the work. The light caught by them was collected in a device called the Michigan infrared combiner. As a result, a high-precision image of the luminary was obtained.

Results of the study

The star Altair, whose photo was taken with a resolution of less than one angular millisecond, appeared as predicted by the theory - oblate in the region of the poles. However, this is not the most interesting thing for scientists. The images showed different parts of the star's surface in terms of brightness. Some spots were seen, dark and light. In addition, there are differences in the brightness of the photosphere of the star in latitude.

The discovered features of Altair have not yet been explained. In the framework of the accepted concepts of uniformly rotating stars, they do not fit. The obtained data require further detailed study with the help of new equipment and special technologies. Optical interferometry methods can be used to study the surface and other stars close to us.

The star Altair in astrology is also linked with the ability to predict, a tendency to think ahead of the age. Perhaps it is not by chance that this luminary encourages scientists to improve their equipment. The inaccessibility of obtaining new knowledge about Altair by old research methods, the inexplicability of certain phenomena within the framework of traditional theories - all this stimulates the movement of scientific thought and available technologies to progress. As before, the alpha Eagle, like the entire constellation, is of interest for amateur astronomers. Close enough location and brightness combined with insufficient knowledge are the reasons for such close attention to Altair. Probably, in a short time scientists will please us with new discoveries connected with this star.