J - K DENIS photometry of a VLTI-selected sample of bright southern stars

Abstract

We present a photometric survey of bright southern stars carried out using the DENIS instrument equipped with attenuating filters. The observations were carried out not using the survey mode of DENIS, but with individual target pointings. This project was stimulated by the need to obtain near-infrared photometry of stars to be used in early commissioning observations of the ESO Very Large Telescope Interferometer, and in particular to establish a network of bright calibrator sources. We stress that near-infrared photometry is peculiarly lacking for many bright stars. These stars are saturatedin 2MASS as well as in regular DENIS observations. The only other observations available for bright infrared stars are those of the Two Micron Sky Survey dating from over thirty years ago. These were restricted to decimations above ≈-30°, and thus cover only about half of the sky accessible from the VLTI site. We note that the final 2MASS data release includes photometry of bright stars, obtained by means of point-spread function fitting. However, this method only achieves about 30% accuracy, which is not sufficient for most applications. In this work, we present photometry for over 600 stars, each with at least one and up to eight measurements, in the J and K filters. Typical accuracy is at the level of 0.m.05 and 0.m.04 in the J and Ks bands, respectively.