Astronomers have measured the space-time warp produced by the intense gravity exerted by a pair of stars as well as found out the mass of a neutron star before it vanished from view.
Ingrid Stairs, an astronomer from the University of British Columbia, and colleagues were the first to witness the disappearance of a neutron star due to the changes caused by gravity in space and time.
The researchers, who reported their discovery in the Astrophysical Journal on Jan. 8, measured the masses of the stars in a binary system called J1906, which is located about 25,000 light-years away from the Earth.
One of these stars is a pulsar, a dense neutron star and collapsed remnant of a supernova, which emits radio wave beams every 144 seconds and completes its orbit of its companion star every four hours.
By tracking the pulsar's motion for five years using five of the biggest telescopes on Earth, the researchers were able to determine its weight as well as quantify the gravitational disturbance.
"Through the measurement of three post-Keplerian orbital parameters we find the pulsar mass to be 1.291(11) M_sol, and the companion mass 1.322(11) M_sol respectively," the researchers wrote.
Although both stars have diameters that are much smaller compared with that of the sun, they are hundreds of times more massive.
Stairs said that although the two stars each have a mass greater than that of the sun, they are still over a hundred times nearer each other compared with the proximity of the Earth to the sun, having an average distance of only 9.3 million miles.
"These two stars each weigh more than the sun, but are still over 100 times closer together than the Earth is to the Sun," Stairs said. "The resulting extreme gravity causes many remarkable effects."
The strength of the gravity that each of the stars exert on each other causes the radio waves that these stars emit to vary in direction and intensity. The intense gravitational force also causes them to wobble around a central axis.
Study resercher Joeri van Leeuwen, an astrophysicist from the Netherlands Institute for Radio Astronomy, said that because the spin axis of the pulsar has wobbled so much, the pulsar can no longer be seen even by the most powerful telescopes on Earth. It could take about 160 years before the pulsar would wobble back into view.
The researcher said that it was the first time that a space-time warp caused by intense gravity was measured and recorded. Its discovery likewise proved that space and time are warped by gravity.
