Constraining neutron star masses and radii using thermonuclear X-ray bursts

Precisely measured neutron star masses and especially radii would provide unique constraints on the properties of cold matter at several times nuclear density. Observations using the Rossi X-ray Timing Explorer suggest that such measurements might be possible using thermonuclear X-ray bursts. Here we discuss the prospects for mass and radius constraints, with a particular focus on potential systematic errors.