A catalog of secondary photometric standard stars around gravitational lenses ^*,**

¹ Royal Observatory of Belgium, Ringlaan 3, 1180 Brussels, Belgium
² Université de Liège, Institut d'Astrophysique et de Géophysique, Allée du 6 Aot, 17, B5C, 4000 Sart Tilman, Liège, Belgium
³ European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Santiago 19, Chile
⁴ School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978, Israel
⁵ Institute of Astronomy & Astrophysics, National Observatory of Athens, Lophos Kouphou - Palaia Penteli, 15236 Athens, Greece
⁶ Department of Physics, University of Crete, PO Box 2208, 710 03 Heraklion, Crete, Greece
⁷ Colton Fellow
⁸ Foundation for Research and Technology-Hellas, PO Box 1527, 711 10 Heraklion, Crete, Greece

Corresponding author: Th. Nakos, tnakos@eso.org

Received: 26 December 2002
Accepted: 28 February 2003

Abstract

We present a catalog of secondary photometric standard stars in the neighborhood of 14 gravitationally lensed quasars. These stars were verified to be non variable using long-term monitoring. The instrumental magnitudes of the new standard stars have been transformed to the Johnson-Cousins  photometric system. For ten gravitational lenses (GLs) we also provide the  mean magnitudes of the integrated flux of all the lens components, for the epochs of the photometric calibration.