Q&A: Supernova Remnants and Neutron Stars

Q:
I am wondering if there is a discovery of neutron star that wasn't detected by radio pulsation. If there is, do you know an example of such star and such detection?

A:
Sco X-1, which is a neutron star in a binary system, was discovered in 1962, about 6 years before radio pulsars, but it wasn't until the Uhuru X-ray satellite flew that astronomers knew for sure that it and a few dozen other sources were neutron stars. (See our Field Guide: Neutron Stars.) The Rosat X-ray observatory also discovered a few isolated neutron stars in the 1990's. (See http://xxx.lanl.gov/abs/multi/astro-ph/0008485 )