Interferometry and asteroseismology: The radius of tau Cet

F. P. Pijpers, T. C. Teixeira, P. J. V. Garcia, M. S. Cunha, M. J. P. F. G. Monteiro, J. Christensen-Dalsgaard

Abstract
We have determined from interferometry the radius of the nearby star tau 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_sun. With this determination tau 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. Based on observations collected at the European Southern Observatory, Chile.

Astronomy and Astrophysics
Volume 406, Page L15
July 2003

DOI: 10.1051/0004-6361:20030837