The
Catalogue of Nebulae and Clusters of Stars was first published in 1786 by
William Herschel in the
Philosophical Transactions of the Royal Society of London. In 1789, he added another 1,000 entries, and finally another 500 in 1802, bringing the total to 2,500 entries. This catalogue originated the usage of letters and catalogue numbers as identifiers. The capital "H" followed with the catalogue entry number represented the item. In 1864, the CN was expanded into the
General Catalogue of Nebulae and Clusters of Stars (GC) by
John Herschel (William's son). The GC contained 5,079 entries. Later, a complementary edition of the catalog was published posthumously as the
General Catalogue of 10,300 Multiple and Double Stars. The small "h" followed with the catalogue entry number represented the item. In 1886, he suggested building a second supplement to the
General Catalogue, but the
Royal Astronomical Society asked Dreyer to compile a new version instead. This led to the publication of the
New General Catalogue (NGC) in 1888, and its two expansions, the
Index Catalogues (IC), in 1895 and 1908. ==See also==