NGC 1851 is a globular cluster in Columba. It was discovered by James Dunlop on May 29, 1826 and cataloged as Dunlop 508.
NGC 1851 appears bright (magnitude 7.14) and large, with a granular 11' diameter halo. The bright, dense, unresolvable, 5'-diameter core is surrounded by progressively fainter and looser concentric rings of stars. The periphery is irregular, and surrounded by a field nicely adorned with 10th and 11th magnitude stars.
NGC 1851 is 39,500 light years from the Sun, and 54,500 light years from the galactic center. Chemical analysis of bright giant stars in the cluster reveals large star-to-star abundance variations in the elements Zr and La. The Zr and La abundances appear to cluster around two distinct values, suggesting that there are two stellar populations in NGC 1851, and indicating that this cluster has experienced a complicated formation history, similar to ω Centauri.