SNR0540-69 is a supernova remnant in the LMC , harbouring a young ( \tau \sim 1600 ~ { } yrs ) radio/optical/X-ray pulsar ( P=50 ms ) .
Ground based H \alpha imaging of the region has shown a unique spiral-like structure centered around the pulsar .
In narrow band HST imaging , the feature seems resolved in a ring-like structure , probably ejected by the progenitor star in a pre-supernova phase ( \geq 10 ^ { 4 } ~ { } yrs ago ) .