Introduction to general relativity this energy loss would be too small to be detectable, but this energy loss was observed in 1974 in a binary pulsar called PSR1913+16. In such a system, one of the orbiting stars is a pulsar. This has two consequences: a pulsar is an extremely dense object known as a neutron star, for which gravitational wave emission is much stronger than for ordinary stars. Also, a pulsar emits a narrow beam of electromagnetic radiation from its magnetic poles. As the pulsar rotates, its beam sweeps over the Earth, where it is seen as a regular series of radio pulses, just
The Magnificent Seven (neutron stars) star radius. Reality is somewhat more complicated, but this oversimplified analysis catches the essence of what is needed in order to measure the neutron star radius: distance, flux and surface temperature. Observing the star thermal emission is therefore crucial. Among all thermally emitting neutrons stars the Magnificent Seven are the only ones with a purely blackbody spectrum. Their clean thermal emission, unmarred by contamination from magnetospheric activity, a surrounding nebula or supernova remnant, makes these sources ideal targets for such a study. Despite many attempts, no radio emission is detected from these sources. The preliminary results from latest deep search