We report on the discovery of a binary pulsar , PSR J1740 - 3052 , during the Parkes multibeam survey .
Timing observations of the 570-ms pulsar at Jodrell Bank and Parkes show that it is young , with a characteristic age of 350 kyr , and is in a 231-day , highly eccentric orbit with a companion whose mass exceeds 11 M _ { \odot } .
An accurate position for the pulsar was obtained using the Australia Telescope Compact Array .
Near-infrared 2.2- \mu m observations make with the telescopes at the Siding Spring observatory reveal a late-type star coincident with the pulsar position .
However , we do not believe that this star is the pulsar ’ s companion , because a typical star of this spectral type and required mass would extend beyond the pulsar ’ s orbit .
Furthermore , the measured advance of periastron of the pulsar suggests a more compact companion , for example , a main-sequence star with radius only a few times that of the sun .
Such a companion is also more consistent with the small dispersion measure variations seen near periastron .
Although we can not conclusively rule out a black-hole companion , we believe the companion is probably an early B star , making the system similar to the binary PSR J0045 - 7319 .