Scientists Discovered The Center Of Gravity Of The Solar System
American astrophysicists have determined the exact location of the center of gravity of the Solar system, which is linked to all measurements of gravitational waves, which scientists use to detect the presence of black holes. The results are published in the Astrophysical Journal.
Gravitational waves are ripples of space-time predicted by Einstein's General theory of relativity. When black holes rotate in pairs, they emit gravitational waves that deform space-time, stretching and compressing it. Gravitational waves were first detected using the LIGO laser interferometric gravitational wave Observatory in 2015.
American astronomers from the NANOGrav project search for gravitational waves by observing regular bursts of radio waves from millisecond pulsars — rapidly rotating neutron stars. Data from 15 years of observations showed that pulsars are extremely stable in terms of pulse frequency, and can be considered not only as interstellar beacons but also as galactic clocks. Any time deviations in pulsar pulses, according to scientists, signal the influence of gravitational waves that bend our Galaxy.
However, scientists have found that existing gravitational models of the Solar system are not suitable for analyzing NANOGrav data, as they regularly give conflicting results.
"It would seem that the more data there is, the more accurate the result should be. But we kept getting big systematic differences in our calculations," lead author Michele Vallisneri, an astronomer at NASA's Jet Propulsion Laboratory (JPL), said in a press release from Vanderbilt University.
"The bottom line is that errors in masses and orbits are converted into pulsar synchronization artifacts that may well look like gravitational waves," explains JPL astronomer and study co-author Joe Simon.
Then the researchers decided to independently calculate the location of the barycenter — the center of gravity of the Solar system, the place where the masses of the Sun itself, all the planets, moons, and asteroids are balanced.
It turned out that it is not in the center of the Sun, as one might assume, but closer to the surface of the star; this is due to the large mass of Jupiter and insufficient consideration of its orbit in models. The NANOGrav project collects data for 15 years, and Jupiter makes a complete revolution around the Sun in 12 years.
By making adjustments to the model, the researchers obtained the center of gravity of the Solar system with an accuracy of 100 meters. According to the authors, this is comparable to the thickness of a human hair on a football field.
Scientists hope that they will now be able to detect gravitational waves from pulsars much more accurately and will discover many new black holes, as well as form a more accurate picture of the shape of our Galaxy.
"We are now localized in space to observe pulsars scattered throughout the Galaxy much better than before," says study leader Stephen Taylor, an Associate Professor of physics and astronomy at Vanderbilt University and a former JPL astronomer. — Using pulsars, we are like a spider sitting in silence in the center of a web and picking up its slightest movement. Knowing where the barycenter of the Solar system is located, we can feel even the slightest "tingling" in the network."
The NANOGrav project continues, and scientists are confident that the new data will soon definitely reveal unknown massive black holes.