An astronomical catalog is a collection of data regarding celestial objects such as stars, galaxies, nebulae, and other celestial bodies. These catalogs typically include information such as coordinates, magnitudes, spectral types, and other relevant data about the objects. Astronomical catalogs are essential tools for astronomers to study and classify celestial objects, track their movements, and identify patterns in the universe. These catalogs can range from general surveys of the entire sky to more specialized catalogs focused on specific types of objects or regions of the sky. They are often used in conjunction with telescopes and computer programs to analyze and interpret data from observations of the night sky.