MONTHLY OBSERVER’S CHALLENGE

Compiled by:

Roger Ivester, North Carolina

&

Sue French, New York

September 2021

Report #152

NGC 6823 & Sh 2-86, Open Cluster & Emission Nebula in Vulpecula

Sharing Observations and Bringing Amateur Astronomers Together

Observer’s Challenge Report: Final

September 2021 OBSERVERS CHALLENGE _NGC 6823 & Sh 2-86

This month’s target:

The nebula surrounding the open cluster NGC 6823 suffers an identity crisis. It’s not NGC 6820, as many sources claim, but rather a small knot of nebulosity 16 arcminutes in position angle 218 degrees (southwest by south) from the bright quadruple star at the cluster’s heart. 

Here is NGC/IC Harold Corwin’s explanation:

NGC 6820 is a small knot of nebulosity, roughly 1′ × 1′, perhaps a reflection nebula around a few young stars or pre-stellar objects. It is specifically NOT the much larger HII region Sharpless 2-86 as has been many times been claimed, nor is it the cluster Collinder 404 = OCl 122, though that may 

represent the stars involved with the nebula. Marth’s original observation with Lassell’s 48-inch reflector mentions only the nebulosity: “F, S, R, bM”. [Faint, small, round, brighter in the middle]

http://haroldcorwin.net/ngcic/ngcnotes.all