Abstract.Simbad is the reference database for identification and bibliography of astronomical objects. It contains identifications, "basic data", bibliography, and selected observational measurements for several million astronomical objects.Simbad is developed and maintained by CDS, Strasbourg. Building the database contents is achieved with the help of several contributing institutes. Scanning the bibliography is the result of the collaboration of CDS with bibliographers in Observatoire de Paris (DASGAL), Institut d'Astrophysique de Paris, and Observatoire de Bordeaux.When selecting catalogues and tables for inclusion, priority is given to optimal multi-wavelength coverage of the database, and to support of research developments linked to large projects. In parallel, the systematic scanning of the bibliography reflects the diversity and general trends of astronomical research.A WWW interface to Simbad is available at: http://simbad.u-strasbg.fr/Simbad.

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Abstract. The Aladin interactive sky atlas, developed at CDS, is a service providing simultaneous access to digitized images of the sky, astronomical catalogues, and databases. The driving motivation is to facilitate direct, visual comparison of observational data at any wavelength with images of the optical sky, and with reference catalogues.The set of available sky images consists of the STScI Digitized Sky Surveys, completed with high resolution images of crowded regions scanned at the MAMA facility in Paris.A Java WWW interface to the system is available at: http://aladin.u-strasbg.fr/.

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Abstract.We present an analysis of dust grain emission in the diffuse interstellar medium of the Small Magellanic Cloud (SMC). This study is motivated by the availability of 170 µm ISOPHOT data covering a large part of the SMC, with a resolution making it possible to disentangle the diffuse medium from the star forming regions. After data reduction and subtraction of Galactic foreground emission, we used the ISOPHOT data together with HiRes IRAS data and ATCA/Parkes combined H  column density maps to determine dust properties for the diffuse medium. We found a far infrared emissivity per hydrogen atom 30 times lower than the Solar neighborhood value. The modeling of the spectral energy distribution of the dust, taking into account the enhanced interstellar radiation field, gives a similar conclusion for the smallest grains (PAHs and very small grains) emitting at shorter wavelength. Assuming Galactic dust composition in the SMC, this result implies a difference in the gas-to-dust ratio (GDR) 3 times larger than the difference in metallicity. This low depletion of heavy elements in dust could be specific of the diffuse ISM and not apply to all the SMC dust if it results from efficient destruction of dust by supernovae explosions.