X-ray detection of SN1988Z with the ROSAT HRI

We report the detection of SN1988Z in X-rays with the ROSAT High Resolution Imager. The inferred X-ray luminosity of about $10^{41}\ergps$ can be well explained by assuming that the supernova occurred in a dense circumstellar medium, consistent with optical observations. SN1988Z is the most distant supernova yet detected in X-rays.