Search

High‐precision pulsar timing relies on a solar system ephemeris in order to convert times of arrival (TOAs) of pulses measured at an observatory to the solar system barycenter. Any error in the conversion to the barycentric TOAs leads to a systematic variation in the observed timing residuals; specifically, an incorrect planetary mass leads to a predominantly sinusoidal variation having a period and phase associated with the planet’s orbital motion about the Sun. By using an array of pulsars (PSRs J0437−4715, J1744−1134, J1857+0943, J1909−3744), the masses of the planetary systems from Mercury to Saturn have been determined. These masses are consistent with the best‐known masses determined by spacecraft observations, with the mass of the Jovian system, 9.547921(2)×10−4M⊙, being significantly more accurate than the mass determined from the Pioneer and Voyager spacecraft, and consistent with but less accurate than the value from the Galileo spacecraft. While spacecraft are likely to produce the most accurat...

Millisecond pulsar B1744−24A (Ter5A) in globular cluster Terzan 5 belongs to the one of the few “windy” binary systems, with unbound material escaping from the companion star and interacting with the pulsar’s magnetosphere. In this work we used two decades of timing data to trace the evolution of the pulsar’s spin and orbital parameters. Also, Ter5A appears to emit strong wide single pulses, with energies 30 or more times the mean pulse energy, with widths comparable to that of the average profile. These pulses occur preferentially shortly before and after the pulsar is obscured by the unbound material from the companion star.

We have undertaken a program of high sensitivity searches for radio pulsar signals from the directions of otherwise‐unidentified gamma ray point sources. Here we present results of observations of five high Galactic latitude (‖ b ‖≳10°) sources discovered by the EGRET instrument aboard the Compton Gamma Ray Observatory. No pulsed radio signals were detected coincident with these sources.

We have searched for radio pulsar companions to 40 nearby OB runaway stars. Observations were made at 474 and 770 MHz with the NRAO 140 ft telescope. The survey was sensitive to long- period pulsars with flux densities of 1 mJy or more. One previously unknown pulsar was discovered, PSRJ2044+4614, while observing towards target O star BD+45,3260. Follow-up timing observations of the pulsar measured its position to high precision, revealing a 9' separation between the pulsar and the target star, unequivocally indicating they are not associated.