Edward Pickering discovered NGC 6807 = HN 51 on 4 Sep 1882 using a direct-vision spectroscope attached to the 15-inch Merz refractor at Harvard College Observatory. His position in Sidereal Messenger, Vol I, No 6 (Oct 1882) is ~30" too far north.

Based on Crossley photographs at Lick, Curtis (1918) wrote, "indistinguishable from a star on the Crossley negatives, but shown to have a minute disk visually with the 36-inch refractor."

400/500mm - 17.5" (7/20/90): at 140x appears as a mag 12 stellar object. Shows an excellent contrast gain with OIII filter. A brighter mag 10.5 comparison star 1.5' NE is similar to NGC 6807 with the OIII filter (so there is a two magnitudes contrast gain with the filter). Increasing the magnification to 286, it appeared to be quasi-stellar with a tiny disc surrounding the central star.

Notes by Steve Gottlieb