PSR J1903+0327
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 03m 05.793213s |
| Declination | +03° 27′ 19.20911″ |
| Characteristics | |
| Spectral type | Pulsar |
| Orbit[1] | |
| Primary | PSR J1903+0327 |
| Companion | Sun-like star |
| Period (P) | 95.174118753 days |
| Eccentricity (e) | 0.436678409 |
| Details[1] | |
| PSR J1903+0327 | |
| Mass | 1.67 M☉ |
| Rotation | 2.14991236434921 ms |
| Age | 1.81 Gyr |
| Sun-like star | |
| Mass | ~1 M☉ |
| Other designations | |
| PSR J1903+0327 | |
| Database references | |
| SIMBAD | data |
PSR J1903+0327 is a millisecond pulsar in a highly eccentric binary orbit.[2]
The pulsar was discovered in an ongoing L-band (1.4 GHz) survey with the 305 m diameter Arecibo radio telescope.[3]
The pulse period is 2.1499 milliseconds, or 465.13 times per second. Analysis of the pulse timing residuals shows a binary orbit with a period of 95.174 days, and a high eccentricity, e = 0.4366. The mass of the companion is ~1 solar mass (M☉), while the pulsar mass is unusually large at 1.67 ± 0.02 M☉;[1] the third largest precisely measured mass after those of PSR J1614−2230 and PSR J0348+0432. A companion, magnitude 18 in near-infrared light of 2.22 μm (the KS band), was recorded by the Gemini North observatory.[2] In 2011, radial velocity measurements made with the VLT confirmed this to be the companion to the millisecond pulsar, the first such system to be observed in the galaxy.
Popular theories for the formation of binary millisecond pulsars require mass transfer onto the rotating neutron star from a white dwarf companion in order to spin it up to periods less than about 10 milliseconds—a process expected to be accompanied by strong tidal forces, producing a highly circular orbit. The main-sequence companion and the eccentric orbit of PSR J1903+0327 do not conform to this expectation. The system is likely to have originated as a triple system. The remnant of the star that transferred mass to the neutron star (its original close companion) was later ejected by a gravitational interaction with the unevolved third member of the system; its present main-sequence companion.
References
- ^ a b c Freire, P. C. C.; Bassa, C. G.; Wex, N.; Stairs, I. H.; Champion, D. J.; Ransom, S. M.; Lazarus, P.; Kaspi, V. M.; et al. (2011). "On the nature and evolution of the unique binary pulsar J1903+0327". Monthly Notices of the Royal Astronomical Society. 412 (4): 2763. arXiv:1011.5809. Bibcode:2011MNRAS.412.2763F. doi:10.1111/j.1365-2966.2010.18109.x. S2CID 67841433.
- ^ a b Champion, David J.; Ransom, S. M.; Lazarus, P.; Camilo, F.; Bassa, C.; Kaspi, V. M.; Nice, D. J.; Freire, P. C. C.; et al. (2008). "An Eccentric Binary Millisecond Pulsar in the Galactic Plane". Science. 320 (5881): 1309–1312. arXiv:0805.2396. Bibcode:2008Sci...320.1309C. doi:10.1126/science.1157580. PMID 18483399. S2CID 6070830.
- ^ Cordes, J. M.; Freire, P. C. C.; Lorimer, D. R.; Camilo, F.; Champion, D. J.; Nice, D. J.; Ramachandran, R.; Hessels, J. W. T.; et al. (2006). "Arecibo Pulsar Survey Using ALFA. I. Survey Strategy and First Discoveries". Astrophys. J. 637 (1): 446–455. arXiv:astro-ph/0509732. Bibcode:2006ApJ...637..446C. doi:10.1086/498335. S2CID 55390845.