A pulsar escaping an ancient open cluster via tidal stripping
Lei Zhang, Xiaoting Fu, Di Li, Emma Carli, Long Wang, Jiaqi Zhao, Craig O. Heinke, Emanuele Dalessandro, Yang Chen, Angela Bragaglia, Duncan R. Lorimer, Ewan D. Barr, Sarah Buchner, Shi Dai, Zhiyu Zhang, Erbil Gügercinoğlu, Alessandro Ridolfi, Jie Zhang, Meng Guo, Mengmeng Ni, Jiale Hu, Yi Feng, Pei Wang, Qijun Zhi
astro-ph.HE, astro-ph.GA, astro-ph.SR
Submitted: 2026-06-26
Comments: Accepted for publication in Science Bulletin on 26 June 2026
Code: https://github.com/BezuidenhoutMC/SeeKAT
Project page: https://wchenastro.github.io/mosaic_web
License: http://creativecommons.org/licenses/by-nc-sa/4.0/
The gist: Open clusters are the primary birthplaces of stars in the Milky Way disk, yet their neutron star progeny are rarely found within them, presumably due to supernova-induced kicks that eject them at
Terminology
Abstract
Open clusters are the primary birthplaces of stars in the Milky Way disk, yet their neutron star progeny are rarely found within them, presumably due to supernova-induced kicks that eject them at birth. Here we report the arcsec-level localization of the pulsar PSR J1921+3745 to the tidal tail of NGC 6791, one of the oldest and most massive open clusters. Our N-body simulation shows that more than 95% of neutron stars formed in such clusters have been ejected. This pulsar's location in the tidal tail indicates it was retained for billions of years before being stripped by Galactic tides. This long-term retention requires low natal kicks, consistent with formation via electron-capture supernova. Our findings capture a rare snapshot of a neutron star transitioning into the Galactic field, identifying tidal stripping of ancient clusters as a verified source of the Galactic neutron star population.
Sources
- A Candidate Open Cluster Pulsar: Timing Analysis of PSR J1922+3745 in NGC 6791
- Nearby open clusters with tidal features: golden sample selection and 3D structure
- Pulsed radio emission from a Central Compact Object
Related papers
- Numerical Studies of Accretion Flows onto a Neutron Star Engulfed in a Massive Star
- Collisionless Accretion of Finite-Angular-Momentum Plasma onto a Spinning Black Hole
- Impact of Magnetic Field Topology on Electromagnetic and Gravitational Waves from Binary Neutron Star Merger Remnants
- XRISM Resolve Spectroscopy of GX 5-1: Constraints on Iron Spectral Features in a Luminous Neutron-Star Binary
- SN 1006: A Cosmic Laboratory for Investigating Shock Acceleration Physics
- Neutrino Spectral Pinching in 3D Core-Collapse Supernovae: Late-Time Convergence, Failed-Explosion Signatures, and Viewing-Angle Dispersion