- John Louis Emil Dreyer (13 February 1852 – 14 September 1926), also Johan Ludvig Emil Dreyer, was a Danish astronomer who spent most of his career working in Ireland. He spent the last decade of his life in Oxford, England.
- New General Catalogue (Wikipedia)
The New General Catalogue of Nebulae and Clusters of Stars (abbreviated NGC) is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including galaxies, star clusters and emission nebulae. Dreyer published two supplements to the NGC in 1895 and 1908, known as the Index Catalogues (abbreviated IC), describing a further 5,386 astronomical objects. Thousands of these objects are best known by their NGC or IC numbers, which remain in widespread use.