Observations of the remnants of three historical (?) supernovae.

Radio maps are presented of the supernova remnants G11.2 0.3, G348.5 + 0.1 and G348.7 + 0.3, all three of which have been suggested as candidates for the remnants of supernovae in the 4th century AD. An HRI X-ray image of G11.2 - 0.3 is also shown. G11.2 - 0.3 is a bright, symmetric shell remnant which looks very like Tycho's or Kepler's SNRs. Its parameters are consistent with an (undetected) supernova explosion 300-500 yr ago, but an alternative interpretation, that is the remnant of the explosion of a massive star in AD 386, cannot be excluded. G348.5 + 0.1 and G348.7 + 0.3 have weaker, more ragged shells than does G11.2 - 0.3 and are probably much older. This would be consistent with one of these two remnants being the relic of the AD 393 explosion.