Foreground Radio Sources and the VSA
Cavendish Astrophysics, Cavendish Laboratory, Madingley Road,
Cambridge, England

Extragalactic radio sources are a foreground that can potentially contaminate observations of primordial structure in the Cosmic Microwave Background. This contamination becomes worse as measurements are made at higher angular resolution. For observations with the VSA we have adopted a scheme of source surveying using the Ryle Telescope to identify these sources, which will then be continuously monitored by a purpose-built, single-baseline interferometer.