X-Ray bursts are seen racing away from a binary star system at nearly the speed of light in measurements from a new radio telescope array, showing relativity in action. The stellar pair, Circinus X-1, displays effects far more powerful than anything that can be created in a laboratory.
This binary star system comprises a neutron star –– the dense remnant of a long-dead star which once exploded –– and an ordinary star. As the two objects orbit around each other every 16.5 days, matter falls from the ordinary star toward the neutron star. This gas and dust heats up, and then, caught in the magnetic field of the neutron star, races outward from each pole at almost the speed of light. The jets shoot out so quickly that they exhibit behavior predicted by Albert Einstein in his Special Theory of Relativity in 1905.
Richard Armstrong, the lead author of the paper reporting the findings said, "The dramatic radio flares happen when the matter Circinus X-1 has violently ejected slows down as it smashes into the surrounding gas."
The flares vary in intensity, with one cycle of pulses running over a regular period of 16 1/2 days, matching the orbital period of the stars. As the two stars orbit in an elliptical path, the distance between the pair varies. At their closest approach to each other, a greater amount of gas is pulled from the normal star to the neutron star than at other times, accounting for the pulses.
Professor Rob Fender, of the University of South Hampton said, "This project [tests] the extremes of physics, density, temperature, pressure, velocity, gravitational and magnetic fields, and are beyond anything achievable in any laboratory on Earth."
Comparing the results of these new measurements with findings about the system from earlier observations could lead astronomers to a whole new understanding of how these types of jets form.
Also known as KAT-7, the telescope is part of the Square Kilometer Array of radio telescopes (SKA). This $3 billion dollar array of radio telescopes is he largest such observatory in the southern hemisphere.
The findings surrounding this system were published in the Monthly Notices of the Royal Astronomical Society (MNRAS).
