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Title: The binary nature of PSR J2032+4127

PSR J2032+4127 is a γ-ray and radio-emitting pulsar which has been regarded as a young luminous isolated neutron star. However, its recent spin-down rate has extraordinarily increased by a factor of 2. Here we present evidence that this is due to its motion as a member of a highly-eccentric binary system with an ~15–M⊙ Be star, MT91 213. Timing observations show that, not only are the positions of the two stars coincident within 0.4 arcsec, but timing models of binary motion of the pulsar fit the data much better than a model of a young isolated pulsar. MT91 213, and hence the pulsar, lie in the Cyg OB2 stellar association, which is at a distance of only 1.4–1.7 kpc. The pulsar is currently on the near side of, and accelerating towards, the Be star, with an orbital period of 20–30 yr. Finally, the next periastron is well constrained to occur in early 2018, providing an opportunity to observe enhanced high-energy emission as seen in other Be-star binary systems.
 [1] ;  [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [5]
  1. Univ. of Manchester (United Kingdom). School of Physics and Astronomy, Jodrell Bank Centre for Astrophysics
  2. Naval Research Lab. (NRL), Washington, DC (United States). Space Science Division
  3. CSIRO Astronomy and Space Science, Epping, NSW (Australia). Australia Telescope National Facility
  4. Columbia Univ., New York, NY (United States). Columbia Astrophysics Lab.
  5. George Mason Univ., Fairfax, VA (United States). College of Science
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Monthly Notices of the Royal Astronomical Society
Additional Journal Information:
Journal Volume: 451; Journal Issue: 1; Journal ID: ISSN 0035-8711
Royal Astronomical Society
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE; National Aeronautics and Space Administration (NASA); National Science Foundation (NSF)
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; binaries; eclipsing; stars; Cyg OB2; starts neutron; MT91 213; Be stars
OSTI Identifier: