Hulse–Taylor pulsar

"[8] Using the Arecibo 305 m dish, Hulse and Taylor detected pulsed radio emissions and thus identified the source as a pulsar, a rapidly rotating, highly magnetized neutron star.

[2][10] The orbit has decayed since the binary system was initially discovered, in precise agreement with the loss of energy due to gravitational waves described by Albert Einstein's general theory of relativity.

The Solar System radiates only about 5,000 watts in gravitational waves, due to the much larger distances and orbit times, particularly between the Sun and Jupiter, and the relatively small mass of the planets.

While there are efforts underway for better measurement of the first two quantities, they saw "little prospect for a significant improvement in knowledge of the pulsar distance," so tighter bounds will be difficult to attain.

Taylor and Weisberg also mapped the pulsar's two-dimensional beam structure using the fact that the system's precession leads to varying pulse shapes.

Evidence of orbital decay in PSR B1913+16. [ 7 ] The data points indicate the observed change in the time of periastron with date, relative to a system not undergoing decay. The parabola illustrates the theoretically expected change according to general relativity .