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Deep Sky Observer's Companion – the online database

 

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NGC 6839 (18,779 of 18,816)

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NGC 6839

NGC 6839, VI 16, h 2057, GC 4521

History and Accurate Positions for the NGC/IC Objects (Corwin 2004)

NGC 6839. WH has one observation of this on 18 August 1784; it was the only object (not a star or double star) that he found that night. His description reads only "A very small cluster of compressed stars." There is nothing like that in the area. JH swept over the spot twice and did not positively identify the cluster either time. The position he gives for one observation is probably that reduced by CH, but he puts plus-minus signs on both coordinates. There are several small clumps of stars in the area that might be WH's object, but none stand out on POSS1, GSC, or DSS.

It is barely possible that this could be M71 (NGC 6838) which is 45 seconds preceding and 53 arcmin north of WH's nominal position. Since WH recorded no other nebulae or clusters that night, we can't say anything about systematic errors without digging into the detailed records of his sweep. The offset to M71 is not unheard of in WH's observations, but it IS rare for him to have such a large position error. And M71 is hardly a "very small" cluster.

Historical observations

William Herschel (c.1784)

Synonyms: H VI-016

Discovered in 1785 by William Herschel with an 18.7-inch f/13 speculum telescope. He called it "a vS cluster of compressed stars."

Published comments

Sulentic & Tifft (1973)

The RNGC (Sulentic and Tifft 1973) notes that this is a nonexistent object. Their coded description reads NO CL DC.

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