2003A&A...406L..15P

We have determined from interferometry the radius of the nearby star τ Cet, using recent observations with the VINCI instrument on VLTI using the siderostats. The limb-darkened disk diameter is determined, with an unprecedented internal precision of 0.5%, to be 1.971±0.009_(int.)±0.05_(ext.)mas, corresponding to a physical radius of 0.773 ±0.004_(int.)±0.02_(ext.) R_☉. With this determination τ Cet becomes a prime target for asteroseismic campaigns to determine its internal structure, and thereby test stellar evolution theory. We discuss implications for asteroseismology and present predictions for oscillation properties.