A trio of «dead stars» confirmed the theory of relativity

© Francesco MereghettiПульсар and white dwarf in the representation of the artistA trio of «dead stars» confirmed the theory of relativity© Francesco Mereghetti

Observation of an unusual family of stars in which one inhabits a pulsar and two white dwarf has helped scientists to prove that gravity slows time and bends space exactly as predicted by the theory of relativity.

«We wondered – «how does the source of gravity?». It may sound strange to an ignorant public, but from the point of view of Einstein, mass and energy are the same thing. If the equivalence principle is violated, then the accumulation of energy, surrounded by a strong gravitational field will be accelerated during the fall is not as the same bundle of energy out of it,» says Anne Archibald (Anne Archibald) from the University of Amsterdam (the Netherlands).

Archibald and her colleagues last week made a presentation at the annual conference of the American astronomical society, held in Washington, DC. They talked about how they were able to use observations of a unique star system J0337+1715 in the constellation Taurus for the most rigid and accurate verification of the so-called principle of equivalence – one of the foundations of the General theory of relativity.

This principle, in its most General and simplified form, States that particles of light have different wavelengths emitted by a distant object in space must come to Earth at the same time, even if they went through a powerful gravitational field. In a similar way to behave and other objects of the visible world, starting with balls and feather in the experiments of Galileo and ending with bundles of energy.

The equivalence principle has been repeatedly tested both on the Ground and in orbit using the us probe Gravity Probe A, the Russian «Radioastron» and a couple of European satellites «Galileo». On the other hand, scientists are not yet sure whether it is observed in the most extreme reaches of space – in «families» of neutron stars or near black holes.

Archibald and her colleagues carried out the first such test, watching a kind of gravitational «matryoshka», a system of three «dead stars» – one pulsar and two white dwarfs.

One white dwarfs and a pulsar rotating around each other at such a small distance that they provide the yet invisible to us, but sufficiently powerful gravitational waves. The situation is further complicated by a second white dwarf orbiting two stars and occasionally obscures their light.

Such a device this star system has allowed scientists to check whether the rights of Einstein. The fact is that if the equivalence principle is not respected, and objects with a stronger gravitational field «falling» faster than their neighbors, then it would orbit the pulsar in some way twisted, stretching to a more distant white dwarf and moving in a circle with him.

These distortions, in turn, could be because of how much of the pulsar signals are delayed at different points in time when he is presumed to be at different points in its elongated orbit. Following this idea, the scientists watched J0337+1715, using American GBT radio telescope and the Gemini optical telescope in Hawaii.

As shown by these observations, signals from the pulsar reach the Earth in approximately equal time intervals, which confirmed Einstein’s theory with the long record of high accuracy, exceeding previous records 50-100 times.

This result, according to the astronomers, once again allows physicists to understand how it is possible to eliminate the contradiction between theory of relativity and quantum physics, which is necessary for the explanation of what happens inside black holes, and understanding of how the universe will evolve in the future.