2026/05/05 by W. Chen, D. Risbud, P. C. C. Freire +20 · 1 voice
Physics and Astronomy · #Astronomy and Astrophysical Research #Pulsars and Gravitational Waves Research #Stellar, planetary, and galactic studies #astro-ph.HE
paper · pdf · doi:10.1051/0004-6361/202659650
openalex publication_date 2026/05/05 · openalex created_date 2026/05/06 · openalex updated_date 2026/07/28
Context. 47 Tucanae is one of the largest, brightest, and closest globular clusters to Earth. It hosts an exotic stellar population with stellar dynamics that indicate a complex evolution history. The cluster contains a large number of X-ray binaries and millisecond pulsars. Aims. Searching for pulsars in this cluster has been an ongoing effort over more than two decades with fruitful results. However, given its large distance relative to the known pulsar population, previous surveys have found only the very brightest sources. Therefore, surveys with increased sensitivity should find many additional pulsars. Increasing the number of pulsars is crucial to investigate the dynamics of this globular cluster and could also lead to the discovery of unusual types of system. Methods. With a significantly increased sensitivity compared to earlier telescopes, MeerKAT is the natural choice to perform new surveys. We carried out two campaigns with different observational cadences to account for the high scintillation along the line of sight to this cluster. All observations were carried out using multi-beam filter-banking user-supplied equipment to increase efficiency and localisation. Results. Here we report the discovery of fifteen new pulsars in 47 Tucanae with MeerKAT. These discoveries bring the total number of known pulsars in this globular cluster to 42, and the MeerKAT discoveries in this cluster to 17. We discuss some of their characteristics, which include preliminary localisations and estimates of orbits for most systems. Highlights include the discovery of 47 Tuc af, a ‘black widow’ pulsar with a short orbital period that was identified optically in 2002 as a candidate binary pulsar, and 47 Tuc ai, an eccentric binary pulsar with a massive companion, a unique system in 47 Tuc to date. Apart from the new systems, we also re-detect and localise 47 Tuc P and V, two elusive, seldom-detected systems that had no precise localisation from a phase-connected timing solution. The localisation of 47 Tuc V places it in a position consistent with a continuum source detected earlier in MeerKAT imaging data.