Pulsars in space act like rotating cosmic lighthouses, continuously emitting regular radio signals. PSR J0846−3533 is exceptional, as it displays three entirely different emission variations simultaneously, a phenomenon that had never been fully and systematically analyzed through observations before.

This research was completed by Prof.WEN Zhigang and YUAN Jianping, together with PhD student WANG Zhen from the Xinjiang Astronomical Observatory, Chinese Academy of Sciences. The relevant findings have been published in The Astrophysical Journal.

Using observational data from Australia’s Parkes 64-meter Radio Telescope, the researchers collected and meticulously analyzed over ten thousand single pulses, confirming that a single pulsar can host three unique emission behaviors at the same time.

This pulsar shows highly variable radiation performance. It may cut off radio emission briefly, just like a lighthouse switching off temporarily. Its pulse profile can also shift its shape rapidly: the trailing part of the pulse shines brighter under normal conditions, while the radiation intensity of the central region surges dramatically after the transition.

Additionally, the pulsar’s brightness undergoes stable periodic flickers, with a full brightness cycle completed every two rotations. This feature was clearly detected in two observation runs separated by three years.

This study expands the sample library of pulsars with coexisting multiple emission phenomena It verifies that mode switching and temporary emission cessation are both triggered by large-scale rearrangement of electric currents within the neutron star magnetosphere. Meanwhile, periodic brightness fluctuations arise from cyclic changes in the efficiency of particle acceleration inside the star. This work clearly distinguishes two completely separate mechanisms behind pulse intensity variations.

The study also reveals obvious differences in activity across different emission zones of the pulsar. It advances our understanding of the extreme magnetic environments around neutron stars and provides critical observational evidence for establishing a unified theory describing pulsar magnetospheric dynamics.

In future work, the researchers will conduct observations with higher sensitivity and longer continuous duration to investigate whether periodic brightness fluctuations vary with emission modes, and further refine theories on pulsar radio emission.

                                                                                                       Harmonic-resolved fluctuation power spectra for PSR J0846−3533.