Object name: NGC6866
NGC 6866 is a beautiful open cluster in Cygnus that doesn't get the attention it deserves. Not only is it a great open cluster of very blue stars they contrast with the background red glow of the H alpha emission that floods much of Cygnus. It is located about halfway between Sadr and Delta Cygni which marks the end of its western wing. It is included in the first Herschel 400 observing program though there's some question whether it was discovered by him or his sister Karoline Lucretia Herschel. Sources seem divided on this issue. Those like the NGC Project crediting William say it was found in 1790 while those such as Seligman say Karoline found it 7 years earlier on July 23, 1783. Neither side seems to address this controversy. Since it is the earlier date I'll go with Karoline as the discoverer.