NGC 20
NGC 20 is a lenticular galaxy in the constellation of Andromeda.
The double name of the galaxy is due to the history of its discoveries: for the first time it was discovered on September 18, 1857, by Irish astronomer R. J. Mitchell, an assistant to William [Parsons, 3rd Earl of Rosse|William Parsons, Lord Rosse]; however, the information was not published until Lawrence Parsons, the son of W. Parsons, did so in 1880. The galaxy was independently rediscovered by Herman Schultz on October 16, 1866, and by Lewis Swift in 1885. As a result, J. L. E. Dreyer cataloged it twice in the New General Catalogue, as NGC 6 and NGC 20.