M19

M19 (NGC 6273 and others) is a Shapley-Sawyer class VIII (https://en.wikipedia.org/wiki/Shapley%E2%80%93Sawyer_Concentration_Class) globular cluster of around 300,000 stars approximately 28,700 light-years away in Ophiuchus. According to https://arxiv.org/pdf/1108.4402, this cluster is 1.1 million times the mass of the sun.

Luminance – 10x300s – 50 minutes – binned 1x1
Luminance – 9x600s – 90 minutes – binned 1x1
RGB – 12:10:11x300s – 60:50:55 minutes – binned 1x1
RGB – 8x600s – 40 minutes each – binned 1x1

425 minutes total exposure – 7 hours 5 minutes

Imaged over twelve nights from March through September, 2021 at the El Sauce Observatory (Rio Hurtado, Chile) with a FLI PL 9000 on a PlaneWave CDK24 at f/6.5 3974 mm.

LRGB - https://www.flickr.com/photos/dcrowson/52984571141/sizes/l/

This data is from Telescope Live (https://telescope.live/) “One-click Observations.”