In the tarantula nebula (NGC 2070), in the galaxy the Large Magellanic Cloud, there is a massive star cluster R136 with the biggest and brightest star of all known to mankind.

Star wolf - Rayet R136a1 - largest known modern astronomy.

R136a1 - Titanic scale object with a surface temperature of more than 50 000 To which weighed at birth 320 Suns. And even today, after a million years of intensive weight loss, star approximately 265 times the mass of our luminary. In this luminosity, it exceeds the Sun 8 700 000 times that means enormous light pressure on its surface. The pressure is, of course, leads to the release into the environment of a significant part of the substance - the strongest stellar wind.

The problem with R136a1 in the first place is that, under the existing theories of stellar evolution, such stars can not be: there is no star can not be formed (actually become a star) at a mass in excess of 150 solar. And R136a1 at birth twice with extra exceeded this limit. That is why it is classified as hypergiant, that is belongs to the class of stars, which appeared after were discovered stars bigger supergiants (which astronomers once relegated in their classifications place biggest stars).

In the Large Magellanic Cloud is just a 10 billion stars in dozens times less than in the milky Way. However, there are many regions of rapid star formation, among which the bright nebula is a Golden Fish, considerably superior in their activity any known region of our Galaxy. It alone has four star wolf - Rayet, and this is a very big mystery. All those stars in our Galaxy 230 (less than one per billion), and in the Large Magellanic Cloud - 100 (one hundred million).

The reasons for such a high concentration of stars in the wolf - Rayet stage in the Large Magellanic Cloud in General and their abundance in the nebula Golden Fish in particular, until recently, remained under question. And now a group of researchers from the Institute of astronomy them. Argelander in Bonn (Germany) under the General guidance of Samburan Banerjee (Sambaran Banerjee) proposed a way out of the situation with unusually massive R136a1 and all cluster R136. According to astronomers, the fact that the star of spectral class a (hypergiant) was formed there very close to each other in a compact binary systems. Therefore, in the further part of them as a result of gravitational interaction of the beginning of the spiral closer, ultimately face and form stars enormous mass and luminosity, such as R136a1 and other

Scientists have modeled the mutual arrangement and interaction of stars in the nebula Golden Fish and cluster R136, proceeding from its original composition 170 thousand stars with a mass not exceeding 150 solar (that before the discovery of hypergiants was considered as the classical limit). Then they allowed the model over 3.5 million years to evolve, and it was discovered curious, namely several cases of mergers stars weighing 150 solar, located in a compact binary systems.

"When the calculations are completed, the light heavyweights ceased to be a mystery, " says Mr Banerjee. - Let's imagine two relatively large stars in orbit around each other. If their initial orbit were moderately elongated, then the light will collide and form one huge star."

As we see, all is simple: limit of normal weight primary stars saved, and all that is above 150 Solar masses, is the result of mergers, so to say "secondary" stars. Thus, hypergiant like R136a1 are just curious exception, not the rule. So what, and "wolves" (facts astronomical observations) are well fed, and "sheep" (astronomical theory) a whole?

Nearly. Practical research systems blue giants in our Galaxy showed that 70% of them exist in the systems of double stars, with the second very solid partner. Moreover, even the 30%that do not have the stars-partners, it seems that once they had - and that is why drifting through the Galaxy with great speed, which developed after the explosion of the second star of their system, which has become a supernova.

In other words, the giants in binary systems - the phenomenon is rather natural, and not accidental. Therefore, the chances to find them outside of the Large Magellanic Cloud is quite large. So far, this has not occurred largely because most often hypergiant exist in dense star clusters and nebulae, where to watch them very difficult because of the light of nearby stars. However, with the progress of astronomical tools we can expect a significant number of discoveries such "heavyweights".

A study accepted for publication in the journal Monthly Notices of the Royal Astronomical Society.

Based on the materials Phys.Org.