A new study published on July 25th in the journal Science uses Albert Einstein’s theory of general relativity to study how gravity acts. The team of researchers from the University of California, Los Angeles, examined the properties of gravity while inspecting the orbit of the star S0-2 around Sagittarius A*, the supermassive black hole that is at the center of our Milky Way galaxy. S0-2, also known as S2, has a three-dimensional 16-year orbit around Sagittarius A*.
Why is the study beneficial and essential?
The team of researchers from UCLA, led by Professor Andrea Ghez, have been studying the star and its orbit for the past 24 years. The team used spectra data obtained by the W.M. Keck Observatory to study the intensity of light emanated by stars to obtain essential data about those stars. At the same time, spectra can reveal the composition of the celestial body.
Until now, the team had obtained images of stars in two dimensions. The spectrograph gives an insight into the third dimension with high accuracy. By having the third dimension data of the star’s orbit, the researchers were able to inspect the laws of gravity near a black hole and if or how Einstein’s theories apply. Einstein’s theory of general relativity affirms that time and space are interweaving near a black hole.
A star near a supermassive black hole prove Einstein’s theory right
The prime object of their study is the photons that S0-2 releases. By measuring their wavelength, which can differ depending upon the speed of the star and the proximity to the black hole, the team could observe the energy the photons needed to slip away from the black hole’s impressive gravity.
An interesting fact is that the scientists measure the photons as they reach Earth, but they need 26,000 years for them to travel to our planet. This means that the circumstances they have been studying happened 26,000 years ago. Another star that orbits around the supermassive black hole is S0-102 in 11 years and six months. The others have orbits that take longer than a human’s lifespan.