An international group of researchers, which included experts from the State astronomical Institute named after P. K. Sternberg, Moscow state University named after M. V. Lomonosov, as well as a number of other Russian and Italian scientific organizations, found that the white dwarf shrinks in the early stages of its evolution. Prior to this, experts assumed that such should occur, however, direct evidence scientists have discovered for the first time.
White dwarf is a end result of the evolution of many stars similar to the Sun. These space objects gradually cool down and it was previously assumed that this could lead to a reduction in their diameter during the first million years of existence. However, to confirm or deny that the white dwarfs are compressed, still did not work, including for the reason that all discovered star of this type has turned into a white dwarf a long time ago. Moreover, until recently, astronomers find it difficult to determine the radius of the distant cosmic bodies with high enough accuracy to test these theories.
In the new study, experts followed a double star HD49798/RX J0648.0-4418, located in the constellation of the Stern at a distance of about two thousand light years from Earth. Astrophysicists have studied located in this system the x-ray source, the nature of which still was not entirely clear — until now it was assumed that he is either a neutron star or very rapidly rotating (and continue to accelerate) a white dwarf. Both these versions have caused issues, and the main reason to doubt that the object is a white dwarf, was the acceleration of its rotation. However, under the assumption of experts, if to explain is the acceleration of the compression space of the body, then everything falls into place.
Scientists believe that their finding will allow you to learn more about how the system HD49798/RX J0648.0-4418, and about what happens to white dwarfs shortly after they become established.
His research scientists published in the journal Monthly Notices of the Royal Astronomical Society.