The binary pulsar: Physical processes, possible companions, and evolutionary histories

Journal Article · Thu Jul 15 04:00:00 EDT 1976 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/154524· OSTI ID:7350954

Smarr, L L; Blandford, R

A study of some aspects of the binary pulsar, PSR 1913+16, is presented in the light of recently reported observational results. If the companion to the pulsar gives a Newtonian contribution to the observed apsidal motion (a helium star or a rotating white dwarf), then it will probably be observable: the former either optically or through the dispersive effects of a stellar wind, and the latter through a secular change in the observed inclination of the orbit. If alternatively the companion behaves dynamically as a point mass (apsidal motion caused solely by general relativity), observations of the O (..nu../c)/sup 2/ frequency shift will furnish a measurement of the masses of the components. In addition, with a tenfold improvement in timing accuracy, the post-Newtonian corrections to the Keplerian ellipse and the effects of aberration could in principle be measured. This would then provide a determination of the orientation of the pulsar spin axis and allow the observation of geodetic spin precession to become a test of general relativity. We also examine the test based on the detection of orbital period changes due to gravitational radiation.Possible evolutionary histories are discussed. The most probable present system consists of two neutron stars, the end result of an X-ray binary phase followed by a double core star phase. In this scenario the long timing age and short period of PSR 1913+16 are shown to be interrelated if the pulsar was the first neutron star formed. To show that other companions are not ruled out on evolutionary grounds, we construct alternate histories leading to either He star, white dwarf, or black hole companions. (AIP)

• Research Organization: Princeton University Observatory
• OSTI ID: 7350954
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 207:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANGULAR MOMENTUM
BINARY STARS
BLACK HOLES
COSMIC RADIO SOURCES
DWARF STARS
GRAVITATIONAL RADIATION
MAIN SEQUENCE STARS
NEUTRON STARS
PARTICLE PROPERTIES
PHYSICAL PROPERTIES
PULSARS
RADIATIONS
SPIN
STAR EVOLUTION
STARS
WHITE DWARF STARS