Because a space warp has tilted the beams of its light towards Earth, a pulsar (a fast rotating neutron star) was pushed out of view. The space-time warp between the gravity of binary stars (a pair of stars) was measured by astronomers. They also determined the mass for the neutron star just before the star disappeared. An international team of scientists including Ingrid Stairs (astronomer and professor of physics at the University of British Columbia) measured the mass of two binary stars within the J binary Pulsar System. Each 144 second, the pulsar spins quickly and produces a beam of radio waves that looks like a lighthouse. In less than 4 hours, the star being studied orbits its companion star. One orbit of the pulsar J 1906 around its companion star (right), with spacetime curvature and blue grid. Credit: Joeri van Leeuwen. Professor Stairs stated: “By accurately tracking the motions of the Pulsar, it was possible to measure the gravitational interactions between these highly compact stars with great precision. Although these two stars are heavier than the Sun they still lie 100 closer than the Earth to the Sun. “The resulting extreme gravity has many amazing effects.” General relativity states that neutron stars spin like tops as they travel through the gravitational well of another nearby star. The pulsar’s orbits travel through curving space-time which has an impact on its spin axis. Joeri van Leuwen (astrophysicist at the Netherlands Institute for Radio Astronomy and University of Amsterdam) is the study leader. She said that “the spin axis of pulsar has become so wobbly due to the enormous mutual gravitational pull,” “The pulsar appears almost invisible even to the most powerful telescopes.” Precession is the first time that a young pulsar like this has vanished. This cosmic spinning top will likely return to view soon, although it could take 160 many years.” Researchers have never been able to determine the mass of any neutron stars. It is located in the J 1906 binary systems and it is the youngest. It is about 25,000 light years from Earth. This study was presented to the American Astronomical Society in Seattle, January 8, and was published in Astrophysical Journal. The Binary Companion of Young, Relativistic Pulsar J by Joeri Van Leeuwen, Laura Kasian, Ingrid H. Stairs, et al., Astrophysical journal, Jan 2015. doi: 10.1088/0004-637X/798/2/118. Video: Geodetic Precession at a Pulsar. This animation is by Joeri Van Leeuwen.
