The Aladin Interactive Sky Atlas

The subject of this symposium, Multi-Wavelength Sky Surveys naturally invokes a discussion of methods of astronomical object identification and classification: Given a set of objects detected at a certain waveband, how does one integrate the new sources with previous data? The ALADIN system (Paillou et al. 1994) of the CDS is a software package designed to tackle this problem: It provides simultaneous access to digitized sky photographs, catalogs and databases to facilitate direct, visual comparison of user data with previously classified data, as well as automatic source extraction and calibration tools.