Evidence against the association of PSR B1706-44 with SNR G343.1-2.3 . ... Abstract An association between the supernova remnant SNR G343.1-2.3 and the pulsar PSR B1706-44 would imply a pulsar velocity greater than 1000 km/s. Observations of the pulsar scintillation made with the Parkes radio telescope at 20 and 70 cm indicate a velocity less than 50 km/s. This fact, coupled with statistical arguments and the morphology of both the SNR and the pulsar plerion, shows that the ...

metrologia The leap second: its history and possible future R. A. Nelson, D. D. McCarthy , S. Malys, J. Levine, B. Guinot, H. F. Fliegel , R. L. Beard and T. R. Bartholome w Abstract. This paper reviews the theoretica l motivatio n for the leap second in the context of the historica l evolutio n of time measurement . Th e periodic insertio n of a leap second step into th e scale of Coordinate d Universal Time (UTC) necessitates frequent changes in comple x timekeepin g systems an d is currentl y th e