M-6 (NGC-6405) is a bright open star cluster located in the constellation of Scorpius, just north of the "stinger". It is sometimes called the "Butterfly Cluster". It lies 1600 light years from Earth and is 12 light years in diameter. It was discovered by de Cheseaux in 1746. Charles Messier observed M-6 in May of 1764, and added it to his catalog as number 6. It contains almost 120 stars, the brightest of which is the Orange colored K-type giant star BM Scorpii, at the upper RH edge of the cluster in the image. M-6 is believed to be about 94 million years old.
This image, acquired on July 27, 2019, is a 30 minute integration of 6 minute exposures through the Celestron C-11 at f/2, using the HyperStar III imaging system and the Starlight Express SXVR-H694C color CCD camera, operating at -10 degrees below ambient temperature and binned 1 X 1. Guided, captured and combined using Maxim DL5 Pro. Post processed using PhotoShop CS2, Gradient XTerminator, StarShrink, Carboni's Astro Tools and NoiseWare.