Thursday, Aug 7, 2025

The globular cluster NGC 6723 was discovered on 2 June 1826 by the Scottish astronomer James Dunlop using the self-built 9-inch reflector at Parramatta observatory near Sydney, Australia. Based on six observations he listed it as number 573 and summarized his description as follows: «A beautiful bright round nebula, about 3.5' diameter, moderately and gradually condensed to the centre. This is resolvable. The moderate condensation, and the bluish colour of the stars which compose it, give it a very soft and pleasant appearance. This is rather difficult to resolve, although the condensation is not very great. In October 1860 German astronomer Julius Schmidt observed this area using the 6.2-inch Plössl refractor at the Athens Observatory and discovered the two bright reflection nebulae NGC 6726 and NGC 6727 around the stars TY CrA and HD 176386. On 15 June 1861 he discovered another nebula (NGC 6729) around star TY CrA. Nebula IC 4812 surrounding the two stars HD 176269/176270 was discovered on 4 August 1899 by American astronomer DeLisle Stewart. He worked at Harvard's Arequipa station in Peru and used the 24" f/5.6 Bruce photographic refractor.