NGC 6836 NGC 6794
Sgr
☀12.9mag
Ø 72'' / 48''

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Forms a pair with ESO 460-030 = MCG -05-46-006 6' NNE. ESO 460-030 is identified as NGC 6816 in RNGC, ESO, PGC, NED and HyperLeda. It appeared very faint, very small, round. Two mag 13.5 stars at the west and northwest edge confuse the observation as well as a mag 10.8 star 1' WSW that is detracting.

John Herschel discovered NGC 6816 = h3800 on 30 Jul 1834 and recorded "eF; R; vlbM; 40"; a *9m north of it; at 6' distance has what may be easily taken for a nebula attached to it, but it is only a little group of vS stars." There is nothing his position, which is 4' due south of ESO 460-029 and 9' south-southwest of ESO 460-030. ESO 460-029 is a better match in position and description -- a mag 10.8 star lies 5' due north along with several other nearby fainter stars.

The question remains that if NGC 6816 = ESO 460-029 how did JH miss brighter ESO 460-030 = PGC 63587? His description suggests he probably noticed this galaxy or the nucleus of the galaxy ("what may be easily taken for a nebula attached to [the star]") but decided it was part of the group of stars. In the GC, JH shortened his description to read "eF; pS; R; vlbM; * np." The 6' separation to the star was not included and it's not clear why he changed the direction to "np" [northwest].

All modern sources, including RNGC, ESO, RC3, PGC, NED and HyperLeda, misidentify ESO 460-030 as NGC 6816. I listed this error in RNGC Corrections #5. See Harold Corwin's identification notes.

400/500mm - 17.5" (6/8/91): very faint, fairly small, very low surface brightness. Forms an equilateral triangle with two mag 13 stars 2.8' SW and 2.8' SSE of center. A close mag 14.5 star is 1' NNE (?). Located 4.5' S of a mag 10.5 star.

600/800mm - 24" (9/23/17): at 200x-375x; faint or fairly faint, moderately large, elongated ~4:3 WNW-ESE, fairly low surface brightness, small slightly brighter nucleus, ~45"x35".

ESO 460-030 (identified as NGC 6816 in most sources), situated 6' NNE, appeared moderately bright, fairly small, irregularly round, small bright core, faint halo 35" diameter. Two stars are superimposed; a mag 13.5-14 star at the west edge [15" from center] and a mag 14.5 star [20" NW]. The halo appears to encompass both stars with averted vision. A bright mag 10.8 star is 1' SW. ESO 460-033, situated 12' NE, appeared fairly faint, moderately large, slightly elongated WNW-ESE, 0.8'x0.65', broad and weak concentration to a slightly brighter core.

24" (9/29/16): at 375x; fairly faint, elongated 5:3 WNW-ESE, ~40"x24", broad concentration with a brighter core. A faint star is off the NW edge [Note: there no star here but a compact companion is at the ESE end - probably my directions are reversed].

In a group with ESO 460-030 6' NNE. This galaxy (usually identified as NGC 6816) appeared fairly faint to moderately bright, small, round, 20"-24" diameter, very small bright nucleus, higher surface brightness than NGC 6816. Two mag 13.5-14.5 stars attached at the west edge interfere a bit and a mag 10.8 star is 1' SW. ESO 460-025, 15' W, appeared fairly faint, fairly small, slightly elongated, ~30"x25", broad weak concentration. A mag 11.5 star is 1.4' SE. ESO 460-033, 12' NE, appeared fairly faint, fairly small, elongated 4:3 WNW-ESE, moderate concentration to a small bright nucleus.

Notes by Steve Gottlieb