Interferometric Measurement of the Angular Sizes of Dwarf Stars in the Spectral Range K3–M4

Abstract

We have used the Palomar Testbed Interferometer to measure the angular diameter of five dwarf stars of spectral types K3-M4. Using the 110 m baseline and observing in H and K bands allows us to measure angular diameters with an accuracy of 2%-8% for stars with apparent angular diameters approaching 1 milliarcsecond. We provide results for both uniform-disk and limb-darkened models and compare our results with theoretical predictions. At the current level of precision our measurements are consistent with most widely accepted models, but further observations should be able to provide useful empirical constraints.