Timing the main-sequence-star binary pulsar J1740-3052

PSR J1740-3052 is a young pulsar in orbit around a companion that is most likely a B-type main-sequence star. Since its discovery more than a decade ago, data have been taken at several frequencies with instruments at the Green Bank, Parkes, Lovell and Westerbork tyelescopes. We measure scattering time-scales in the pulse profiles and dispersion measure changes as a function of binary orbital phase and present evidence that both of these vary as would be expected due to a wind from the companion star. Using pulse arrival times that have been corrected for the observed periodic dispersion measure changes, we find a timing solution spanning from 1997 November to 2011 March. This includes measurements of the advance of periastron, , and the change in the projected semimajor axis of the orbit, x , and sets constraints on the orbital geometry. From these constraints, we estimate that the pulsar received a kick of at least similar to 50 km s-1 at birth. A quasi-periodic signal is present in the timing residuals with a period of 2.2 times the binary orbital period. The origin of this signal is unclear.