NGC 6520 & Barnard 86

Open Cluster & Dark Nebulae, Sagittarius

September 2022. Observatorio El Sauce, Chile

NGC 6520 is an open cluster in the constellation Sagittarius, superimposed upon the Large Sagittarius Star Cloud. It is magnitude 9.0, diameter 5 arc minutes and class G. It has about 25 stars of magnitude 9 to 12. The dark nebula Barnard 86 lies near its western edge. Both can be seen together just right and above center in this image. These lie close to Baade’s Window, which is an area of the sky with relatively low amounts of interstellar dust along the line of sight from Earth. This area is considered an observational “window” as the normally obscured Galactic Center of the Milky Way is visible in this direction. It is named for astronomer Walter Baade, who first recognized its significance. This area corresponds to one of the brightest visible patches of the Milky Way.

Telescope: Astro Physics 155EDF (TCC) f5.4
Mount: Astro Physics 1600GTO
Camera: FLI PL29050 / CFW2-7
Guider: Agena Starguide II / ZWO ASI178MM
Filters: Astrodon II 50mm LRGB

L: 50×5 mins = 285 mins, R: 24×5 mins = 120 mins, G: 24×5 mins = 120 mins, B: 24×5 mins = 120 mins

Total Imaging Time: 10h 10m

Data Imaged remotely over 4 nights during September 2022.
Imaged from Observatorio El Sauce, Chile, in partnership with Fred Espenak.
Data acquisition & Processing by David Churchill.