arXiv · 2610.29838
PSR J0653+0443: An Eclipsing Millisecond Pulsar in an Extremely Eccentric Double Neutron Star System
Abstract
Double neutron star (DNS) systems emit gravitational waves (GW) as they orbit each other, with waveforms dependent on their orbital properties \cite{Poisson+2014grav.book.....P}. The number of DNS systems surviving binary star evolution in the Milky Way and the distribution of their orbital parameters are fundamental questions for GW astronomy and binary evolution studies. Here, we report the discovery of a new Galactic field DNS system, PSR J0653+0443, comprising two ~1.4 $M_\odot$ components in an extremely eccentric orbit $e=0.992387$, $P_{\rm orb}=79.084$ d. Its unique orbital dynamics include a 46-minute transit from true anomaly $θ=-90^\circ$ to $90^\circ$ and striking periastron relative motion (maximum acceleration 1.11~km~s$^{-2}$, peak speed 1.14$\times$10$^6$~m~s$^{-1}$. The pulsar undergoes an 85-second conjunction eclipse, indicating a nearly edge-on binary orbit. Short-term variations in the periastron advance induce significant pulse arrival time modulation spanning -2.91 to +2.49 ms --- at least an order of magnitude larger than that observed in any other DNS system. From this modulation, the non-relativistic periastron advance rate is constrained to $-1.5^{+0.9}_{-0.8}\times10^{-4}$ deg yr$^{-1}$. The extreme orbital eccentricity can only be attributed to a large kick velocity imparted during the iron-core collapse supernova of the progenitor of the second component. The predicted detection probability of such a PSR J0653+0443-like DNS system is $\lesssim 5 \times 10^{-3}$, implying that our discovery of this system challenges current understanding of binary evolution. This extraordinary DNS system emits periodic gravitational wave bursts, with the GW energy flux peaking at 0.357 mHz. This makes it an ideal target for the future LISAmax mission.
Explore related subjects
Keep this discovery
Explore connections, maps & timelines
Z. L. Yang, J. L. Han, L. G. Hou, Z. W. Chen, Y. G. Gong, Y. L. Guo, Y. J. Lu, C. Zhang, K. Y. Song, B. Liu, D. Lai, C. Wang, W. Q. Su, P. F. Wang, X. P. You, N. N. Cai, Q. Gao, W. C. Jing, B. Wang, H. G. Wang, T. Wang, J. Xu, Y. Yan, D. J. Zhou. 2026-10-21. PSR J0653+0443: An Eclipsing Millisecond Pulsar in an Extremely Eccentric Double Neutron Star System. https://arxiv.org/abs/2610.29838
Cite the original work for its findings. Save a collection to share your selection of sources.