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 350kyr, and is in a 231-d, highly eccentric orbit with a companion
whose mass exceeds 11Msolar. An accurate position for the
pulsar was obtained using the Australia Telescope Compact Array.
Near-infrared 2.2-μm observations made 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
companion of the pulsar, because a typical star of this spectral type
and required mass would extend beyond the orbit of the pulsar.
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 cannot conclusively rule out a black hole
companion, we believe that the companion is probably an early B star,
making the system similar to the binary PSR J0045-7319.
- BINARIES: GENERAL
- STARS: LATE-TYPE
- STARS: MASS-LOSS
- PULSARS: GENERAL
- PULSARS: INDIVIDUAL: PSR J1740-3052
- X-RAYS: STARS