At https://phys.org/print418368262.html … modeling upsets theory. A pulsar in a far away galaxy send out x-ray beams that pass earth every 1.37 seconds. Scientists originally thought it was a massive black hole – but it pulsed. Hence it is now designated as a pulsar. Is this all the difference between a hypothetical black hole and a pulsar?
A pulsar emits a rotating form of electromagnetic radiation, like the beam of a lighthouse. They are said to rotate at a stable speed yet they can suddenly speed up in brief glitches. What causes the pulsars to glitch and wobble? Modeling doesn't appear to agree with the explanation on offer. A rethink is required, we are told. Might also be true of black holes. The must also be emitting electromagnetic radiation. Why?