PSR B0943+10 is a pulsar 2,000 light years from Earth[2] in the direction of the constellation of Leo.
[8] Ongoing research at the University of Vermont discovered that the pulsar was found to flip roughly every few hours between a radio bright mode with highly organized pulsations and a quieter mode with rather chaotic temporal structure.
[9][10] Moreover, the observations of the pulsar performed simultaneously with the European Space Agency's XMM-Newton X-ray observatory and ground-based radio telescopes revealed that it exhibits variations in its X-ray emission that mimic in reverse the changes seen in radio waves – the pulsar has a weaker non-pulsing X-ray luminosity during the radio bright mode and is actually brighter during the radio quiet mode emitting distinct X-ray pulses.
[10] Such changes can only be explained if the pulsar's magnetosphere (which may extend up to 52,000 km from the surface) quickly switches between two extreme states.
[9] In 2006, a research group from Peking University published a paper suggesting that the pulsar may actually be a low-mass quark star with mass around 0.02 M☉.