An emission-state-switching radio transient with a 54-minute period

M.C. thanks E. Sadler, R. Ekers, D. Huber, L. Oswald and S. Oslowski for valuable discussions. This paper makes use of data from MeerKAT (project ID DDT-20210125-MC-01) and Parkes (project ID PX079). M.C. thanks SARAO for the approval of the MeerKAT DDT request, the science operations, CAM/CBF and operator teams for their time and effort invested in the observations, and the ATNF for scheduling observations with the Parkes radio telescope. The MeerKAT telescope is operated by the South African Radio Astronomy Observatory, which is a facility of the National Research Foundation, an agency of the Department of Science and Innovation (DSI). TRAPUM observations used the FBFUSE and APSUSE computing clusters for data acquisition, storage and analysis. These clusters were funded and installed by the Max-Planck-Institut für Radioastronomie and the Max-Planck-Gesellschaft. This scientific work uses data obtained from telescopes within the Australia Telescope National Facility (https://ror.org/05qajvd42), which is funded by the Australian Government for operation as a National Facility managed by CSIRO. The Parkes radio telescope (Murriyang) is part of the Australia Telescope National Facility (https://ror.org/05qajvd42), which is funded by the Australian Government for operation as a National Facility managed by CSIRO. We acknowledge the Wiradjuri people as the Traditional Owners of the observatory site. Inyarrimanha Ilgari Bundara/the Murchison Radio-astronomy Observatory is the site of the CSIRO ASKAP radio telescope. We acknowledge the Wajarri Yamaji as the Traditional Owners and native title holders of the observatory site. Operation of ASKAP is funded by the Australian Government with support from the National Collaborative Research Infrastructure Strategy. ASKAP uses the resources of the Pawsey Supercomputing Research Centre. Establishment of Inyarrimanha Ilgari Bundara, the CSIRO Murchison Radio-astronomy Observatory, ASKAP and the Pawsey Supercomputing Research Centre are initiatives of the Australian Government, with support from the Government of Western Australia and the Science and Industry Endowment Fund. This paper includes archived data obtained through the CSIRO ASKAP Science Data Archive, CASDA (http://data.csiro.au). The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. Construction and installation of VLITE was supported by the NRL Sustainment Restoration and Maintenance fund. M.C. acknowledges support of an Australian Research Council Discovery Early Career Research Award (project number DE220100819) funded by the Australian Government. Parts of this research were conducted by the Australian Research Council Centre of Excellence for Gravitational Wave Discovery (OzGrav), project number CE170100004. R.M.S. and N.H.-W. acknowledge support through Australian Research Council Future Fellowships FT190100155 and FT190100231, respectively. T.E.C. and S.G. acknowledge that basic research in Radio Astronomy at the US Naval Research Laboratory is supported by 6.1 Base Funding. K.M.R acknowledges support from the Vici research programme ‘ARGO’ with project number 639.043.815, financed by the Dutch Research Council (NWO).

Open access funding provided by the University of Sydney.

The data that support the findings of this study are available on Zenodo at https://doi.org/10.5281/zenodo.10989868 (ref. ⁷²).

Extended Data Fig. 1 𝑃−𝑃˙ diagram showing the spin-period against the period derivative for neutron stars as reported in the ATNF pulsar catalog, and published long period transients.

The timing was performed using TEMPO2 (ref. ⁵²). Specific Python scripts used in the data analysis are available on request from M.C.

The authors declare no competing interests.