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A 110-ms pulsar, with negative period derivative, in the globular cluster M15The discovery of a 110-ms pulsar, PSR2127+11, in the globular cluster M15, is reported. The results of nine months of timing measurements place the new pulsar about 2 arcsec from the center of the cluster, and indicate that it is not a member of a close binary system. The measured negative value of the period derivative is probably the result of the pulsar being bodily accelerated in our direction by the gravitational field of the collapsed core of M15. This apparently overwhelms a positive contribution to the period derivative due to magnetic braking. Although the pulsar has an unexpectedly long period, it is argued that it belongs to the class of 'recycled' pulsars, which have been spun up by accretion in a binary system. The subsequent loss of the pulsar's companion is probably due to disruption of the system by close encounters with other stars.
Document ID
Document Type
Reprint (Version printed in journal)
External Source(s)
Wolszczan, A. (Arecibo Observatory PR, United States)
Kulkarni, S. R. (California Institute of Technology Pasadena, United States)
Middleditch, J. (Los Alamos National Laboratory NM, United States)
Backer, D. C. (California, University Berkeley, United States)
Fruchter, A. S. (Princeton University NJ, United States)
Dewey, R. J. (California Institute of Technology, Jet Propulsion Laboratory, Pasadena; Cornell University Ithaca, NY, United States)
Date Acquired
August 14, 2013
Publication Date
February 9, 1989
Publication Information
Publication: Nature
Volume: 337
ISSN: 0028-0836
Subject Category
Distribution Limits