2025/12/04 by Roger W. Romani, Romani, Roger W., Maya Beleznay +7 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #Pulsars and Gravitational Waves Research #Scientific Research and Discoveries
paper · pdf · doi:10.48550/arxiv.2512.05099
openalex publication_date 2025/12/04 · openalex created_date 2025/12/06 · openalex updated_date 2026/07/28
We report on new orbit-minimum photometry and revised radial-velocity fitting that provide an improved measurement of the mass of the neutron star (NS) in pulsar PSR~J0952-0607 at MNS = 2.35± 0.11 M_\odot. With its fast spin and unusually low magnetic field, this NS has evidently experienced unusual evolution, likely connected with its high mass, which is now 2.5σ above that of the heaviest pulsar with a white dwarf companion, as measured by Shapiro delay techniques. By tightening the mass measurement, we also raise the maximum (commonly called Tolman-Oppenheimer-Volkoff) NS mass to M\rm TOV > 2.27 M_\odot(2.12 M_\odot) at 1σ(3σ) confidence, which improves bounds on the dense-matter equation of state. While the statistical error decreases and systematic issues should be modest, uncertainties remain; we comment briefly on these factors and prospects for further improvement.