21 year timing of the black-widow pulsar J2051−0827

Abstract

Timing results for the black-widow pulsar J2051−0827 are presented, using a 21-year dataset from four European Pulsar Timing Array telescopes and the Parkes radio telescope. This dataset, which is the longest published to date for a black-widow system, allows for an improved analysis that addresses previously unknown biases. While secular variations, as identified in previous analyses, are recovered, short-term variations are detected for the first time. Concurrently, a significant decrease of ∼2.5×10−3 cm−3pc in the dispersion measure associated with PSR J2051−0827 is measured for the first time and improvements are also made to estimates of the proper motion. Finally, PSR J2051−0827 is shown to have entered a relatively stable state suggesting the possibility of its eventual inclusion in pulsar timing arrays.