John Herschel discovered NGC 6708 = h4021 on 9 Jun 1836 and recorded "F; S; R; 15"; the following of a group." On 6 Jun 1837 he logged "pB; R; 90"; gpbM." This observation was not included in the main table of the Cape of Good Hope catalogue but added in a "supplementary nebulae" list at the end (h4016 to h4021), which Dreyer identified as "h o n" (Herschel Omitted Object) in the NGC.

600/800mm - 30" (11/3/10 - Coonabarabran, 264x): bright, moderately large, slightly elongated N-S, 1.0'x0.9', moderately concentrated to a small bright core. Forms a pair with NGC 6707 6' SSW. Situated in a fairly rich star field.

Notes by Steve Gottlieb