NGC 6904 is a magnitude +11.9 open star cluster located in the constellation Vulpecula.
The cluster was discovered by British astronomer John Herschel using a 47.5 cm (18.7 inch) f/13 speculum reflecting telescope at Windsor Road in Slough, Berkshire, on the 18th August 1828.
Right Ascension 20h 21m 48.3s, Declination +25° 44' 22"
