Radio waves come in all strengths across the universe, from the extremely faint signals sent by distant spacecraft such as the Voyagers and Pioneers to the extremely powerful waves generated by rapidly spinning neutron stars called pulsars. (sciencemag.org)
Hailey, too, admits that of the dozen sources detected he only feels certain half are black holes — the remaining six, he says, display behavior that could also be explained as emissions from rapidly spinning neutron stars called millisecond pulsars. (scientificamerican.com)
Pulsars are fast - spinning neutron stars left over after massive stars explode as supernovae. (newscientist.com)