Messier 4 - NGC 6121

Messier 4 - NGC 6121

105 subs at 5 seconds each – 30 ISO, Bortle 2 – 3

Total Data: 8½ minutes

Taken with Celestron Origin using OLV software.

West Taratahi Hall, Chester Rd, Masterton, NZ.

Wednesday 20th May 2026

Stacked and processed in Siril

Messier 4 or M4 (NGC 6121) is a globular cluster in the constellation of Scorpius, located near the star Antares. It was discovered by Philippe Loys de Chéseaux in 1745 and catalogued by Charles Messier in 1764. It was the first globular cluster in which individual stars were resolved.