VizieR is a comprehensive astronomical database that provides access to bibliographic data, observational data, and catalogs of celestial objects visible from Earth.

The SDSS is a major astronomical survey that aims to study the evolution of galaxies, map the large-scale structure of the universe, and search for exoplanets.

NED (NASA/IPAC Extragalactic Database) is a comprehensive database that provides information about extragalactic objects, including galaxies, quasars, and active galactic nuclei.

The Gaia mission is a space-based astrometry mission that aims to create a precise three-dimensional map of the Milky Way, including the positions, distances, and motions of stars.

SIMBAD (Set of Identifications, Measurements, and Bibliography for Astronomical Data) is a comprehensive database that provides information about stars, including their positions, magnitudes, spectral types, and variability.

The HST archive is a repository of HST observations, including images, spectra, and other data, which are available to the scientific community for research purposes.

The Exoplanet Archive is a comprehensive database that provides information about exoplanets, including their host stars, orbital parameters, and physical properties.

The CXO archive is a repository of CXO observations, including X-ray images, spectra, and other data, which are available to the scientific community for research purposes.

NED (NASA/IPAC Extragalactic Database) is a comprehensive database that provides information about galaxies, including their positions, magnitudes, redshifts, and morphological types.

The SST archive is a repository of SST observations, including infrared images, spectra, and other data, which are available to the scientific community for research purposes.

The Open Supernova Catalog is a comprehensive database that provides information about supernovae, including their positions, magnitudes, redshifts, and host galaxies.

The ALMA archive is a repository of ALMA observations, including millimeter and submillimeter images, spectra, and other data, which are available to the scientific community for research purposes.

NED (NASA/IPAC Extragalactic Database) is a comprehensive database that provides information about quasars, including their positions, magnitudes, redshifts, and host galaxies.

The VLT archive is a repository of VLT observations, including optical and infrared images, spectra, and other data, which are available to the scientific community for research purposes.

NED (NASA/IPAC Extragalactic Database) is a comprehensive database that provides information about AGN, including their positions, magnitudes, redshifts, and host galaxies.