1 Introduction

The DENIS project aims to survey the entire southern hemisphere simultaneously in three photometric bands, I (Gunn-i, $\rm0.8\, \mu m$), J ( $\rm 1.25\, \mu m$) and $K_{\rm s}$ ( $\rm 2.15\, \mu m$) with a spatial resolution of $1\hbox{$^{\prime\prime}$ }$ in I and $3\hbox{$^{\prime\prime}$ }$ in the J and $K_{\rm s}$bands, and limiting magnitudes of I=18, J=16, $K_{\rm s}=14$. See Epchtein et al. ([1999]) for the first general release of DENIS data. Here we present a catalogue of DENIS Point Sources towards the Magellanic Clouds, requiring that objects are detected in at least two of the three photometric bands. At the distance of the Magellanic Clouds, $(m-M)=18.45\pm0.1$ for the LMC and $(m-M)=19.0\pm0.1$ for the SMC according to Westerlund ([1997]), our catalogue contains: (1) all Asymptotic Giant Branch stars (AGB), except those with shells optically thick at $2~\mu$m and the faintest stars at the very beginning of the Early AGB branch (E-AGB), (2) upper Red Giant Branch stars (RGB), (3) most of the super-giants except those brighter than I=10.5, J=8.0, $K_{\rm s}=6.5$ because they saturate the detectors, (4) relatively bright post-AGB stars. The catalogue will thus be a major tool for statistical studies of the post-main sequence stellar populations of the Magellanic Clouds. Dwarfs and giants are the main galactic sources seen in front of the Magellanic Clouds (Ruphy et al. [1997]). Compared to earlier spectroscopic and photometric surveys of the Magellanic Clouds for red giants and super-giants, and for stars on the AGB, probably we find a few hundreds times more sources, for several reasons: (1) previous surveys were not sensitive enough (Westerlund [1960], [1961]; Sanduleak & Philip [1977]; Westerlund et al. [1978], [1981]; Rebeirot et al. [1983]), (2) they were spatially limited (see e.g. Blanco et al. [1980]; Blanco & McCarthy [1990]), (3) they were restricted to a peculiar type of objects (e.g. Hughes [1989] in his search for Miras variables, Rebeirot et al. [1993] in their search for carbon stars). About 1/4 of the sources discovered in these surveys were later observed in the JHK(L) infrared photometric bands (e.g. Hughes & Wood [1990]; Costa & Frogel [1996]). DENIS provides simultaneous $IJK_{\rm s}$ observations of the entire Clouds, with a good sensitivity, and connecting for the first time the traditional optical and infrared wavelengths domains by simultaneous observations.

Section 2 describes the instrument characteristics and the observing technique. Section 3 describes the data reduction procedure in the two "data analysis centers'' with particular attention to: flat and bias subtraction, point spread function, and astrometric and photometric calibration. Section 4 discusses the quality of the data with regard to the selection criteria applied and to the completeness reached. Section 4.2 discusses in particular the foreground sources belonging to our Galaxy. Finally, Sect. 5describes the content of the catalogue and Sect. 6 gives conclusive remarks. The catalogue is available through the Strasbourg Astronomical Data Center (CDS); it carries the number II/228.