M6 is a large, bright open cluster visible
to the naked eye in the eastern portion of Scorpius. About 80 stars have been
identified as members of the cluster, which is estimated to be 51 million years old.
It measures 20 light-years in diameter and is located at a distance of 2,000
light-years. NGC 6357 is the large emission nebula in the lower right portion of the
image, which appears bright here but is faint visually, requiring a large aperture and a
dark sky to be appreciated. The large region of red nebulosity between M6 and NGC
6357 is Sh2-13, centered around the open cluster NCG 6383.
Instrument:
Celestron 8" Schmidt camera
F-ratio: f/1.5
Exposure: 10 minutes, guided by ST-7E through an 80mm guide scope
Film: Elite Chrome 200
Date: July 14, 1999, 9:48 PM PDT
Location: Grandview Campground, White Mountains, California, USA