CCD camera and automatic data reduction pipeline for the Mercator telescope on La Palma

Abstract

In this paper we present the development of a CCD imager for the modern 1.2m MERCATOR telescope dedicated to long term monitoring of variable astrophysical phenomena. This instrument is a result of the collaboration of the Observatory of Geneva with the Institute of Astronomy in Leuven. After a technical description of the main components of the CCD camera system, the text will focus on the automatization of the observations and subsequent data reduction. The telescope itself is an altazimuth mounted 1.2 m Ritchey-Chretien telescope and is operated in a semi-automatic mode. The system executes a predefined sequence of observations, that only need occasional checking of data quality by the astronomer. The observation software is written in a FORTRAN based interpreter language (INTER) running on a UNIX system that communicates with the astronomer via GUIs implemented in Perl/Tk. The data reduction is integrated into one package and includes pre-reduction, photometric and astrometric calibration, extraction, catalogue preparation and archiving. This allows to have a GUI driven reduction that is both flexible and robust. The preliminary reduced data give the astronomers an indication of the quality of their observations, so that they can adjust their program or camera settings during the same night.