The star "hid" in the fold of space-time for 150 years

Astrophysics from the Netherlands Institute of Radio Astronomy and the University of Amsterdam have published very interesting results of five-year observation of the double pulsar J1906, which in 2004 appeared on the star-sky map. Scientists have managed to calculate the mass of the binary system. At the end of the observations, the pulsar was again out of sight, which corresponds to Einstein's general theory of relativity and the thesis about the curvature of the fabric of space-time under the influence of gravity.

The J1906 system consists of two neutron stars with a mass of 1.291 and 1.322 solar masses and a diameter of 10-20 km, which are at a very small distance from each other (100 times less than the distance from the Earth to the Sun) and move very quickly, making a revolution around a friend for 4 hours. In this case, the pulsar itself rotates around its axis at a speed of seven revolutions per second.


Mass of pulsar and companion stars
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Accordingly, giant gravitational perturbations arise in the system, which directly affect the pulsar orbit. This is a very shaky orbit, and the axis of rotation is constantly changing due to the curvature of space-time.

The double pulsar is located in the Terzyan 5 globular star cluster at a distance of 7670 parsecs from the Sun. Discovered in 2004 by an observatory in Arecibo (a pulsar suddenly appeared on a sky map), the pulsar emitted radio waves every 144 ms. The explosion, in the result of which the pulsar was formed, occurred only 100 thousand years ago, its binary system had not yet managed to enter a stable state.

Earth telescopes can register a pulsar only if its radio emission is directed in our direction. But the star that had entered the curved space tilted its orbit, so that now it became invisible to us.



In 2005-2009, about a billion revolutions made by the pulsar were recorded from five terrestrial radio telescopes. Astrophysicists have studied in detail the gravitational interaction between the stars and made up the interaction model. According to their calculations, the pulsar will again be visible from Earth in the region of 2170.

Perhaps this is the most vivid demonstration of the curvature of space-time, received to date.

“The results of our work are very important, since it is extremely difficult to determine the mass of a celestial body in its free flight. This is a problem because mass measurement is necessary for an accurate understanding of gravity, as a force that is closely related to the behavior of space and time at all levels of our Universe, ”said Dr. Joeri van Leeuwen of the Netherlands Institute of Radio Astronomy at press conference.

The study was published in the Astrophysical Journal and presented at the 225th meeting of the American Astronomical Society.