Jul 11, 2021
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.
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.
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.