This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.We present a phase-resolved ROSAT HRI X-ray light curve of the dwarf nova OY Car in quiescence. The X-ray flux is eclipsed at the same time as the optical eclipse of the primary, and the region of X -ray emission is comparable in size to the white dwarf. We use subsequent optical observations to update the orbital ephemeris of the system.We thank Jakob Engelhauser for his help with the difficult scheduling of the ROSAT observations. We acknowledge the data analysis facilities provided by the Starlink Project, which is run by CCLRC on behalf of PPARC. GWP is in receipt of a University of Central Lancashire research studentship
