Messier 18 - The Small Sagittarius Star Cloud

Messier 24 is a massive region in the constellation Sagittarius and is the only star cloud in the Messier Catalog. It has an apparent magnitude of about 2.5, which means it is easily visible to the naked eye from a dark sky location. Due to light pollution along my southern horizon, I cannot see it with my own eyes, but fortunately my telescope can! Like I said earlier in my Messier 18 blog post, the field of view was quite nice, which allowed me to capture two objectes at the same time. When photographed with narrowband filters, the region reveals bright red hydrogen alpha emission from ionized hydrogen, along with doubly ionized oxygen emission, which often appears blue and gives the image a lightning like appearance. These cool emissions originate from nebulae embedded within the star cloud. At the time I captured this object using a broadband filter, I was not yet aware of these narrowband features. This is definitely an object I would like to revisit in the near future.

I captured this during a Messier Marathon I did in August 2025.