Neutron star concluded that the radiation comes from a neutron star at the stage of accretion. In 1967, Jocelyn Bell Burnell and Antony Hewish discovered regular radio pulses from PSR B1919+21. This pulsar was later interpreted as an isolated, rotating neutron star. The energy source of the pulsar is the rotational energy of the neutron star. The majority of known neutron stars (about 2000, as of 2010) have been discovered as pulsars, emitting regular radio pulses. In 1971, Riccardo Giacconi, Herbert Gursky, Ed Kellogg, R. Levinson, E. Schreier, and H. Tananbaum discovered 4.8 second pulsations in an X-ray source in the constellation
Radio-quiet neutron star Star), "INS" (Isolated Neutron Stars). Defined as thermally emitting neutron stars of high magnetic fields, although lower than that of magnetars. Identified in thermal x-rays, and thought to be radio-quiet. Compact Central Objects in Supernova remnants (CCOs in SNRs) are identified as being radio-quiet compact x-ray sources surrounded by supernova remnants. They have thermal emission spectra, and lower magnetic fields than XDINSs and magnetars. Radio-quiet neutron star A radio-quiet neutron star is a neutron star that does not seem to emit radio emissions, but is still visible to Earth through electromagnetic radiation at other parts of the spectrum, particularly x-rays