A braking index for PSR 0540-69

Abstract

Optical pulse timing observations of the young pulsar PSR 0540-69 in the LMC using the 4-m Anglo-Australian Telescope over a 2-yr intervalhave yielded accurate period parameters for the pulsar. The derivedvalue of the braking index is 2.01 + or - 0.02, much less than themagnetic-dipole value of 3.0.