Archive for September 2021

NGC 6823/Sh 2-86: Open Cluster/Emission Nebula in Vulpecula: September Observer’s Challenge Report #152

September 13, 2021

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 maven 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 

The position of NGC 6820 is 19h 42m 27.9s  +23° 05′ 15″. Consider this a bonus object if you’d like.

Information above compiled by Sue French

Jaakko Saloranta: Observer from Finland (Pencil Sketch)

Stargazing Simplified: An Original Article From Sky & Telescope Magazine: Submitted by Guest Host and Author: James Mullaney

September 6, 2021