A catalog of bright calibrator stars for 200-m baseline near-infrared stellar interferometry

Abstract

We present in this paper a catalog of reference stars suitable for calibrating infrared interferometric observations. In the K band, visibilities can be calibrated with a precision of 1% on baselines up to 200 meters for the whole sky, and up to 300 meters for some part of the sky. This work, extending to longer baselines a previous catalog compiled by Borde et al. (2002, A&A, 393, 183), is particularly well adapted to hectometric-class interferometers such as the Very Large Telescope Interferometer (VLTI, Glindemann et al. 2003, Proc. SPIE, 4838, 89) or the CHARA array (ten Brummelaar et al. 2003, Proc. SPIE, 4838, 69) when one is observing well-resolved, high-surface brightness objects (K < 8). We use the absolute spectro- photometric calibration method introduced by Cohen et al. (1999, AJ, 117, 1864) to derive the angular diameters of our new set of 948 G8-M0 calibrator stars extracted from the IRAS, 2MASS and MSX catalogs. Angular stellar diameters range from 0.6 mas to 1.8 mas (median is 1.1 mas) with a median precision of 1.35%. For both the northern and southern hemispheres, the closest calibrator star is always less than 10 ◦ away.