Precision Timing of Psr J0437 4715: an Accurate Pulsar Distance, a High Pulsar Mass, and a Limit on the Variation of Newton’s Gravitational Constant

Analysis of 10 years of high-precision timing data on the millisecond pulsar PSR J0437 4715 has resulted in a model-independent kinematic distance based on an apparent orbital period derivative, Ṗb, determined at the 1.5% level of precision (Dk 1⁄4 157:0 2:4 pc), making it one of the most accurate stellar distance estimates published to date. The discrepancy between this measurement and a previously published parallax distance estimate is attributed to errors in the DE200 solar system ephemerides. The precise measurement of Ṗb allows a limit on the variation of Newton’s gravitational constant, jĠ/Gj 23 ; 10 12 yr . We also constrain any anomalous acceleration along the line of sight to the pulsar to ja /cj 1:5 ; 10 18 s 1 at 95% confidence, and derive a pulsar mass, mpsr 1⁄4 1:76 0:20 M , one of the highest estimates so far obtained. Subject headinggs: pulsars: individual (PSR J0437 4715) — stars: distances — stars: neutron