Timing observations of the binary pulsar PSR 0655+64.

The authors present the results of 6.5 years of timing observations of PSR 0655+64 and derive an ephemeris and precise position. The very small period derivative of 6.9×10^-19s s^-1 implies a spin-down age of 4.5×10⁹yr and a magnetic field of 1.2×10¹⁰ G. Kulkarni's optical identification of the companion star is confirmed. The measured eccentricity of 7.5×10^-6 may be partly due to to a general relativistic delay caused by the passage of pulses through the gravitational field of the companion star. A significant relativistic advance of the periastron should be observable over a period of ⪉30 yr.