The most famous scientists of planetary nebulae have the correct spherical form. However, there are exceptions - for example, the nebula Fleming 1, like intricate lace veil, with visible seal in the center. Recently, scientists have discovered why it is so unusual is the fact that it created two identical white dwarf.

After completing the evolutionary cycle, our Sun forms a planetary nebula. A burning plasma cloud spread, burning planets of the Solar system, and the star prevratitsya at the end of the metamorphoses in a small, thick and slow cooling by radiation of a white dwarf. The so-born planetary nebula, well studied and observed through telescopes objects.

This is actually not the galactic nebulae, which are much larger and longer than its outer space, out of which stars are born. The name "planetary nebula" is a tribute to tradition. So continue to call reset external gas covers a dying sun-like stars in the final stage of evolution in a white dwarf. They are spherically symmetric, sometimes a circle on clearance, but there are among them those that have amazing, lace and whimsical form is beautiful planetary nebula Fleming 1 (Fleming 1).

It is surrounded by the edges symmetric twisted curls plasma curls, formed a dynamic jets flying jets of plasma. Whimsical the configuration of this nebula demanded explanations, and astronomers under the leadership of Henry Boffin the European southern Observatory, based in Chile, combines the latest monitoring Fleming 1, performed on the Very large telescope (VLT) with the picture of computer modeling, built in accordance with certain assumptions about the internal structure of the source that gave rise to the delicate ligature amazing nebula. And these assumptions were unusual - they laid the idea of twin star, that is, two different stars interacting in the centre of this planetary nebula. The full report of this study was recently published in the journal Science

Known planetary nebulae show the correct spherical form. Meet other, rather distorted configuration, in the projection is similar to the crumpled cube or rectangular block. Such a variety of forms ensured by internal reasons: gravitational interactions of stars are members of binary system, or the fact that applaudie planet violate spherical distribution of plasma and magnetic field of the Central star is the effect on the moving plasma flows that form of distortion of the spherical planetary nebula...

Exploring the Central region unusual nebula Fleming 1 using the VLT and analyzing the glow from there, astronomers have found a double star. And to be precise, two white dwarf, which completes a full rotation around a common center of gravity for 1.2 earth days. Double stars in the Universe are common, so that scientists were not surprised - that is why in planetary nebulae they must be.

Feature Fleming 1 is that the double star in the center is the aforementioned pair of white dwarfs. It happens, according to observations, quite rare. Double stars tend to be different, and one of them had "Matures" and swells in the nebula. For example, the companion white dwarf can be a red giant. However, their evolutionary metamorphosis always spaced in time.

But if a double star system consists of the stars of the same type, they "old" much slower their life cycle will last for ten billion years! This is the case in planetary nebulae Fleming 1, in which both stellar component homogeneous, and must lose their luminosity slower dissimilar stars. So at least the extra ten billion years this system is guaranteed. According to calculations Henry Boffin, one of the stars by weight less than half of our Sun, and her twin quite a bit inferior to the first. These results formed the basis of the model.

"The origin of beautiful and complex shapes nebula Fleming 1 and objects, like her, many decades has been the subject of controversy, " says Henry Boffin. Astronomers had assumed that this nebula in the centre of the binary star - the truth, it was believed that light distant from each other, with the orbital period in decades. Our observations and model has allowed to study the unusual system in detail and look deep into her bowels. This double star in several thousand times closer than was considered".

So, if a star with a mass of up to eight Solar masses completes its life cycle, it swells and rejects its outer shell, which flies away from the hot dense inner core, which will cool only by radiation. It is a bright glow and therefore visible in a telescope.

Unlike a typical planetary nebula, is extremely picturesque Fleming 1 is centrally symmetric configuration. Its substance erupts SIPS from both poles of the Central binary system in the form of S-shaped curved jets. According to the latest research, the structure of the nebula Fleming 1 arises from the close interaction between the two stars. Computer modeling correctly showed structural features lace nebula, reproduced analytically, but very similar to the natural object!

One of the authors, Brent Masalski, evaluating the results, said, "we have Before us a model case of the steam room of the Central star, for which computer simulation correctly predicted the picturesque form the surrounding nebula".

Physical explanation that happened was asked the following: presence of a pair of white dwarfs is fundamentally important to explain the observed patterns of the nebula. With the ageing of these two, once normal former stars of the main sequence, they expanded, and eventually one of them "turned into a vampire"draining the substance of the second component and, apparently, accelerating its transformation itself into a white dwarf.

Well, while gas from the star victims flowed towards "vampire"surrounding its accretion disk. The orbital movement of the stars were implemented in collaboration with this disk, and his plane continuously cheated on tilt, rotate slower-spinning top. This movement is called precession, and it is formed unusually curved S-shaped jets, symmetrical to the center Fleming 1, reproduced in computer simulations.

Pictures of real planetary nebula Fleming 1, obtained at the VLT, revealed a new structural features of the studied nebula: knobby heterogeneous "ring" substances in its inner part. Such rings were found in the other collections of double stars; they are "identification sign of" the availability of double star systems. Henry Boffin sums up: "Our results confirm once more the importance of interaction between the components of the binary in the education structures of planetary nebulae, and can, and in shaping the nebula".