NGC 6857 is an emission nebula and star-forming region located in the constellation Cygnus. It is located in the Perseus Arm of the Milky Way galaxy.
It was discovered by William Herschel on 6 September 1784. It was later observed by John Herschel, who believed it to be a star cluster. He described it as "A small bunch of very minute Milky Way stars, so small as almost to look nebulous; north preceding is another." Rudolph Minkowski would conclude in 1946 that NGC 6857 was a nebula.
The nebula is divided into two parts. The two parts are designated at Sh 2-99 and Sh 2-100. It visually resembles a planetary nebula.
Despite not being a galaxy, a PGC number was assigned to it by HyperLEDA.
