Image specs

Object: NGC6231

Image Credit: Andrew Kemp

Telescope: Meade 6" ACF SCT 1,524mm @ f/10

Camera: Nikon D5100

Settings: ISO200, 120x15s subs

Processing: Deep Sky Stacker, StarTools, Photoshop. No calibration frames were used in this image.

Location

NGC 6231 is an open cluster in Scorpius. In fact, it sits along the scoprion's tale, right next to Zeta Scorpii. NGC6231 is located at RA 16h54m and Dec -41° 48'. According to wikipedia, it is ~5,600LY from Earth and moving towards us at 22km/s.

Composition

According to https://freestarcharts.com/ngc-6231:

NGC 6231 is a bright open cluster of approx. 120 stars spread over 15 arc minutes of sky in Scorpius. With a combined magnitude of +2.6, this group of stars is visible to the naked eye and a stunning sight through binoculars and telescopes. At its heart are numerous hot luminous fifth and sixth magnitude blue-white type B supergiants. It appears similar to a smaller version of M45, the famous Pleiades cluster in Taurus.