Unified Celestial Catalogue

The Unified Celestial Catalogue for Deep-Sky Objects  (abbreviated UCC) is an of  compiled by Rasmus Koppel in 1789. The UCC originally contained 6,120 objects, including, , and. Koppel revised the UCC twice in 1796 and 1801, describing a further 2,032 objects. Many of the most prominent deep-sky objects are labeled under UCC numbers, which remains in widespread use.

Since 1937, the UCC has been maintained and revised by the World Astronomers Federation, an international amateur astronomers society. Since 1933, the WAF has added over another 5,452 objects especially south of the in which Koppel had not cataloged thoroughly.

The original UCC contained many errors, but since its maintenance and revision over nearly a century have resulted in one of the most widely used and accurate astronomical catalouges in use today