[15] Rudolf Minkowski, in the same issue of The Astrophysical Journal as Baade, advanced spectral arguments claiming that the "evidence admits, but does not prove, the conclusion that the south preceding star is the central star of the nebula".

The period of 33 milliseconds and location of the Crab Nebula pulsar NP 0532 was discovered by Richard V. E. Lovelace and collaborators on 10 November 1968, at the Arecibo Radio Observatory.

Soon after the discovery of the Crab Pulsar, David Richards discovered (using the Arecibo Telescope) that it spins down and, therefore, loses its rotational energy.

A subsequent study by them, including William D. Brundage, also found that the NP 0532 source is located at the Crab Nebula.

[20] A radio source was also reported coincident with the Crab Nebula in late 1968 by L. I. Matveenko in Soviet Astronomy.

[21] Optical pulsations were first reported by Cocke, Disney and Taylor using the 36-inch (91 cm) telescope on Kitt Peak of the Steward Observatory of the University of Arizona.

[24] Jocelyn Bell Burnell, who co-discovered the first pulsar PSR B1919+21 in 1967, relates that in the late 1950s a woman viewed the Crab Nebula source at the University of Chicago's telescope, then open to the public, and noted that it appeared to be flashing.

Bell Burnell notes that the 30 Hz frequency of the Crab Nebula optical pulsar is difficult for many people to see.

[25][26] In 2007, it was reported that Charles Schisler detected a celestial source of radio emission in 1967 at the location of the Crab Nebula, using a United States Air Force radar system in Alaska designed as an early warning system to detect intercontinental ballistic missiles.

[25] However, Schisler's detection was not reported publicly for four decades due to the classified nature of the radar observations.