BEIJING, March 17 (Xinhua) — A new study has found that the way space-time rotates around a dead star confirms another prediction of Einstein’s general theory of relativity, according tomedia reports. Einstein had predicted a phenomenon called “reference system drag”, also known as the Cold Ze-Tilzon effect, that space-time would rotate around a large, rotating mass object. It’s like dipping the earth into honey, and as the earth rotates, the honey around it will be rotated.
The figure shows a concept of the drag phenomenon of the reference system dragging produced by the constantly rotating white dwarf in the binary system PSR J1141-6545.
Satellite experiments have detected reference system drag in the gravitational field of the Earth’s rotation, but the effect is so weak that it is difficult to measure. Around larger, more gravitational-field objects such as white dwarfs and neutron stars, the chances of observing this phenomenon should be greater.
Scientists targeted PSR J1141-6545, a young pulsar about 1.27 times the mass of the sun. It is located in the constellation of Flies, near the famous Southern Cross, about 10,000 to 25,000 light-years from Earth.
A pulsar is a fast-rotating neutron star that emits radio waves outwards in the direction of the magnetic pole. (Neutron stars are the remains of a star who dies in a dramatic explosion such as a supernova explosion, with a gravity that is strong enough to squeeze protons together with electrons to form neutrons.) )
The pulsar PSR J1141-6545 revolves around a white dwarf of similar mass to the sun. White dwarfs are parts of the kernel left behind by medium-sized stars running out of fuel and dying, dense and similar in size to Earth. Our sun will one day become a white dwarf, as will more than 90 percent of the stars in the Milky Way.
The pulsar orbits the white dwarf in a very short orbit and can turn at speeds of up to 1 million kilometers per hour, completing a revolution in less than five hours. The orbit is very close to the white dwarf, and the distance is only slightly larger than the diameter of the sun at its maximum.
For nearly 20 years, researchers have been using Australia’s Parkes Observatory and UTMOST radio telescopes to measure the time the pulsar emits pulses to reach Earth with an accuracy of less than 100 microseconds. They found that the pulsar and the white dwarf shifted around each other over a long period of time.
After ruling out other possible causes, the scientists concluded that the phenomenon was caused by the drag effect of the reference system: the fast-rotating white dwarf caused the drag effect on space-time, which in turn led to a gradual change in the orientation of the pulsar’s orbit. Based on the extent of the drag of the reference system, the researchers calculated that the white dwarf would spin around the axis 30 times an hour.
Previous studies have shown that the white dwarf star formed earlier than pulsars. The theoretical model predicts that the precursors of the pulsar had dumped material the size of 20,000 Earths into the white dwarf for about 16 million years before the supernova explosion that formed the pulsar, speeding up the rotation of the white dwarf.
“In the PSR J1141-6545 system, pulsars are younger than white dwarfs, and such systems are quite rare. The researchers note that the new study “confirms the hypothesis that a treaty put forward 20 years ago about how such binary systems formed.”
The researchers point out that they used the reference system to drag the phenomenon to learn more about the rotating star that caused the phenomenon. In the future, they can also use similar techniques to analyze dual neutron star systems to learn more about their internal composition. “We’ve been looking at the twin neutron star system for more than 50 years, but we still don’t have a clue. “The density of matter inside neutron stars is much higher than that can be achieved in the lab, so if we could use the technology to study dual neutron systems, we would certainly learn a lot of new physics,” the researchers said. “
The detailed findings were published online January 30 in the journal Science.