An Eccentric Binary Millisecond Pulsar in the Galactic Plane
Abstract
Binary pulsar systems are superb probes of stellar and binary evolution and the physics of extreme environments. In a survey with the Arecibo telescope, we have found PSR J1903+0327, a radio pulsar with a rotational period of 2.15 milliseconds in a highly eccentric (e = 0.44) 95-day orbit around a solar mass (M⊙) companion. Infrared observations identify a possible main-sequence companion star. Conventional binary stellar evolution models predict neither large orbital eccentricities nor main-sequence companions around millisecond pulsars. Alternative formation scenarios involve recycling a neutron star in a globular cluster, then ejecting it into the Galactic disk, or membership in a hierarchical triple system. A relativistic analysis of timing observations of the pulsar finds its mass to be 1.74 ± 0.04 M⊙, an unusually high value.
- Publication:
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Science
- Pub Date:
- June 2008
- DOI:
- 10.1126/science.1157580
- arXiv:
- arXiv:0805.2396
- Bibcode:
- 2008Sci...320.1309C
- Keywords:
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- Astrophysics
- E-Print:
- 28 pages, 4 figures inc Supplementary On-Line Material. Accepted for publication in Science, published on Science Express: 10.1126/science.1157580