PSR J0437-4715 is a pulsar. Discovered in the Parkes 70 cm survey, it remains the closest and brightest millisecond pulsar (MSP) known. The pulsar rotates about its axis 173.7 times per second and therefore completes a rotation every 5.75 milliseconds. It emits a searchlight-like radio beam that sweeps past the Earth each time it rotates. Currently the most precisely located object outside of the Solar System, PSR J0437-4715 is 156.3 parsecs or 509.8 light years distant.
This pulsar is distinguished by being the most stable natural clock known and is debatably more stable than man-made atomic clocks. Its stability is about one part in 1015. Two other pulsars, PSR B1855+09 and PSR B1937+21 are known to be comparable in stability to atomic clocks, or about 3 parts in 1014.
PSR J0437-4715 is the first MSP to have its X-ray emission detected and studied in detail. It is also the first of only two pulsars to have the full three-dimensional orientation of its orbit determined.
Optical observations indicate that the binary companion of PSR J0437-4715 is most likely a low-mass helium white dwarf. The pulsar is about 1.8 solar mass (M☉) and the companion is about 0.25 M☉. The pair revolve around each other every 5.75 days in nearly perfect circular orbits.
- Johnston, Simon; Lorimer, D. R.; Harrison, P. A.; Bailes, M.; Lynet, A. G.; Bell, J. F.; Kaspi, V. M.; Manchester, R. N.; et al. (1993). "Discovery of a very bright, nearby binary millisecond pulsar". Nature. 361 (6413): 613–615. Bibcode:1993Natur.361..613J. doi:10.1038/361613a0.
- Deller, A. T.; Verbiest, J. P. W.; Tingay, S. J.; Bailes, M. (2008). "Extremely High Precision VLBI Astrometry of PSR J0437-4715 and Implications for Theories of Gravity". The Astrophysical Journal. 685: L67. arXiv:. Bibcode:2008ApJ...685L..67D. doi:10.1086/592401.
- Timing stability
- Hartnett, J. G.; Luiten, A. N. (2011). "Colloquium: Comparison of astrophysical and terrestrial frequency standards". Reviews of Modern Physics. 83: 1. arXiv:. Bibcode:2011RvMP...83....1H. doi:10.1103/RevModPhys.83.1.
- Becker, Werner; Trümper, Joachim (1993). "Detection of pulsed X-rays from the binary millisecond pulsar J0437 - 4715". Nature. 365 (6446): 528. Bibcode:1993Natur.365..528B. doi:10.1038/365528a0.
- Van Straten, W.; Bailes, M.; Britton, M.; Kulkarni, S. R.; et al. (2001). "A test of general relativity from the three-dimensional orbital geometry of a binary pulsar". Nature. 412 (6843): 158–160. arXiv:. Bibcode:2001Natur.412..158V. doi:10.1038/35084015. PMID 11449265.
- Bell, J. F.; Bailes, M.; Bessell, M. S. (1993). "Optical detection of the companion of the millisecond pulsar J0437–4715". Nature. 364 (6438): 603. Bibcode:1993Natur.364..603B. doi:10.1038/364603a0.
- Verbiest, J. P. W.; Bailes, M.; van Straten, W.; Hobbs, G. B.; et al. (2008). "Precision Timing of PSR J0437-4715: An Accurate Pulsar Distance, a High Pulsar Mass, and a Limit on the Variation of Newton's Gravitational Constant". The Astrophysical Journal. 679: 675. arXiv:. Bibcode:2008ApJ...679..675V. doi:10.1086/529576.
- Tables of Binary and Millisecond Pulsars