SUNSET: 
0
Photographer:
massimo.difusco
Location of Photo:
Rio Hurtado (Chile)
Date/Time of photo:
02/06/2025 03:30
Equipment:
Data acquired at Chilescope: ASA Newton 500 @1900mm, ASA DDM85 equatorial Mount, FLI PL16803 CCD camera, Astrodon R/G/B filters
Description:
Messier 23 (also known as M23 or NGC 6494) is a bright, large open star cluster located in the constellation Sagittarius. It lies at a distance of 2150 light years from Earth and has an apparent magnitude of 6.9. Messier 23 has a radius of 15 to 20 light years and contains 176 confirmed members. Most stars in the cluster are between 10th and 13th magnitude, and about 100 stars are brighter than magnitude 13.5. M23 has an estimated age of at least 220 million years, which makes it one of the older known open clusters in our galaxy. Messier 23 occupies an area of 27 arc minutes of apparent sky, roughly the size of a full Moon, and has a linear diameter of 15 light years. It is classified as Trumpler I 2 r cluster.
