Astronomers figured out to what size can grow «dead stars»

© Goethe-Universitat Frankfurt Gravitational waves generated during the merger of pulsarsAstronomers figured out to what size can grow «dead stars»© Goethe-Universitat Frankfurt

The analysis of data collected by the LIGO detector for gravitational during the merger of the two pulsars have shown that the neutron star may weigh a little more than two solar masses, according to a paper published in the Astrophysical Journal Letters.

«The theory allows us to predict many things, but she very often needs experimental data in order to eliminate or reduce certain gaps in it. For this reason, it is surprising that observations in only one merger of neutron stars and the theory helped us to solve the mystery that our colleagues have long argued in the past,» says Luciano Rezzolla (Luciano is below.) from the Institute of theoretical physics in Frankfurt (Germany).

Gravitational LIGO detector, the gravitational waves discovered in September of 2015, made his next epoch-making discovery in August of last year, revealing fluctuations of space-time generated by the merger of two neutron stars – the «burned» remains of normal stars, exhausted all the reserves of hydrogen and helium.

The pressure within neutron stars is so high that the electrons in them start to merge with the protons, turning into exotic matter, whose properties are still not entirely clear. The part of physicists believes that it is similar to the liquid, while others believe that it is an analogue of matter that filled the Universe in the first moments after the Big Bang.

For this reason, scientists did not know what the minimum and maximum size and mass could have such luminaries, and where lies the border separating them from white dwarfs and black holes. The discovery of gravitational waves, as noted Rezzola, helped to solve both these problems.

Certain properties of these fluctuations of space-time, according to him, depend on of which matter is composed converging or colliding neutron stars and other compact objects. Other traits, on the contrary, do not depend on structure of colliding «dead stars», but only on their mass.

This feature of gravitational waves has allowed scientists to determine, looked like the product of a collision between two neutron stars that gave rise to the outbreak GW170817 — it was a small black hole and to compute the exact limit for the maximum mass of its progenitors.

As shown by their calculations, the maximum mass of the neutron star should not exceed of 2.01-2.16 mass of the Sun in that case, if it doesn’t rotate around its axis. This figure is considerably smaller for pulsars and other spinning «dead bodies», whose maximum mass of more solar by only 20% during rapid rotation.

This assessment, as noted Rezzola, occupies an intermediate position among the other theoretical predictions – previously, some scientists thought that neutron stars can’t weigh more than 1.5 Suns, and other astrophysicist believed that they may be about three times heavier than our sun.

In other words, the heaviest neutron star in our galaxy, the pulsar J0348+0432, crept close to the boundary, computed Rizzoli and his colleagues – she is 201% heavier than the Sun. Further observation of gravitational waves and the discovery of new pulsars, as scientists hope, will help to verify this actually.

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