Messier Deep-Sky Catalog

Charles Messier's 18th-century catalogue of "nebulae and star clusters" — the deep-sky objects (galaxies, globular and open clusters, diffuse and planetary nebulae, and supernova remnants) that famously are not comets. Each row gives the Messier number, common name, object kind, host constellation, and New General Catalogue (NGC) cross-identification. Every row is read live at build time from OnlyCSharp.Data.Catalogs.PhysicsAndAstronomy.MessierObjects.MessierCatalog.AllObjects. Authored as .razor; rendered to static HTML.

Source: Charles Messier, "Catalogue des Nébuleuses et des Amas d'Étoiles" (1774–1781) — an 18th-century work in the PUBLIC DOMAIN by age. Object kinds and NGC cross-identifications are well-established astronomical facts consistent with NASA's public catalogs (U.S. Government, not copyrighted). License / dedication proof: https://www.nasa.gov/nasa-brand-center/images-and-media/ — NASA's own media-usage statement (attribution not required). We cite anyway; the citation is the proof we owed no credit.