We present Australia Telescope Compact Array ( ATCA ) observations of the supernova remnant ( SNR ) G296.8–00.3 .
A 1.3-GHz continuum image shows the remnant to have a complex multi-shelled appearance , with an unusual rectangular strip running through its centre .
H i absorption yields a kinematic distance to the remnant of 9.6 \pm 0.6 kpc , from which we estimate an age in the range ( 2 - 10 ) \times 10 ^ { 3 } yr .
The ATCA ’ s continuum mode allows a measurement of the Faraday rotation across the band , from which we derive a mean rotation measure towards the SNR of 430 rad m ^ { -2 } .
We consider possible explanations for the morphology of G296.8–00.3 , and conclude that it either has a biannular structure , as might be produced through interaction with an asymmetric progenitor wind , or that its appearance is caused by the effects of the surrounding interstellar medium .

We argue that the adjacent pulsar J1157–6224 is at a similar distance as the SNR , but that a physical association is highly unlikely .
The pulsar is the only detectable source in the field in circular polarization , suggesting a method for finding pulsars during aperture synthesis .