PSR J0437−4715
PSR J0437−4715 is a pulsar. Discovered in the Parkes 70 cm survey,[5] 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.[3]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pictor |
| Right ascension | 04h 37m 15.81476s[1] |
| Declination | −47° 15′ 08.6242″[1] |
| Apparent magnitude (V) | 20.98±0.09[2] |
| Characteristics | |
| Spectral type | Pulsar |
| Astrometry | |
| Proper motion (μ) | RA: 121.453 mas/yr Dec.: 71.457 mas/yr |
| Distance | 509.8 ly (156.3[3] pc) |
| Details | |
| Mass | 1.44[4] M☉ |
| Other designations | |
PSR B0435−47, 1RXS J043714.5−471503 | |
| Database references | |
| SIMBAD | data |
This pulsar is distinguished by being the most stable natural clock known and is debatably more stable than man-made atomic clocks.[6][7] 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.[8] It is also the first of only two pulsars to have the full three-dimensional orientation of its orbit determined.[9]
Optical observations indicate that the binary companion of PSR J0437-4715 is most likely a low-mass helium white dwarf.[2] The pulsar is about 1.4 solar mass (M☉)[4] and the companion is about 0.25 M☉.[1] The pair revolve around each other every 5.75 days in nearly perfect circular orbits.[10]
See also edit
References edit
- ^ a b c 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 (1): 675. arXiv:0801.2589. Bibcode:2008ApJ...679..675V. doi:10.1086/529576. S2CID 5207918.
- ^ a b 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. S2CID 44962125.
- ^ a b 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 (1): L67–L70. arXiv:0808.1594. Bibcode:2008ApJ...685L..67D. doi:10.1086/592401. S2CID 8362572.
- ^ a b Reardon, D. J.; Hobbs, G.; Coles, W.; Levin, Y.; et al. (2016). "Timing analysis for 20 millisecond pulsars in the Parkes Pulsar Timing Array". Monthly Notices of the Royal Astronomical Society. 455 (2): 1751–1769. arXiv:1510.04434. Bibcode:2016MNRAS.455.1751R. doi:10.1093/mnras/stv2395.
- ^ 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. S2CID 4324763.
- ^ . Archived from the original on 2016-03-05. Retrieved 2009-05-09.
- ^ Hartnett, J. G.; Luiten, A. N. (2011). "Colloquium: Comparison of astrophysical and terrestrial frequency standards". Reviews of Modern Physics. 83 (1): 1–9. arXiv:1004.0115. Bibcode:2011RvMP...83....1H. doi:10.1103/RevModPhys.83.1. S2CID 118396798.
- ^ 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. S2CID 4342134.
- ^ 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:astro-ph/0108254. Bibcode:2001Natur.412..158V. doi:10.1038/35084015. PMID 11449265. S2CID 4363384.
- ^ . Archived from the original on 2016-03-03. Retrieved 2009-05-09.