At a Glance
Object: Messier 25
Type: Open Star Cluster
Constellation: Sagittarius
Distance: 2,000 light-years
Catalog: Messier
Best Season: Summer
Messier 25 is a bright open star cluster located in the constellation Sagittarius. It sits in one of the richest regions of the Milky Way, where countless stars, clusters, and nebulae fill the summer night sky. Because Sagittarius lies in the direction of the center of our galaxy, this part of the sky is packed with deep-sky treasures.
M25 is an open cluster, meaning it is a loose group of stars that formed together from the same cloud of gas and dust. Unlike globular clusters, which are ancient, tightly packed balls of stars, open clusters are younger and more spread out. The stars in M25 are still traveling through space together, though over time, gravity from the Milky Way will gradually pull the group apart.
Messier 25 is located approximately 2,000 light-years from Earth. Even at that distance, it is bright enough to be seen with binoculars under decent skies. Through a telescope or in a wide-field image, M25 appears as a scattered collection of bright stars, with several colorful members adding extra interest to the view.
The cluster was first recorded by Philippe Loys de Chéseaux in 1745 and later included by Charles Messier in his famous catalog in 1764. Messier’s goal was to list fuzzy objects that comet hunters might confuse with comets, but many of those entries turned out to be some of the most beautiful deep-sky objects in the sky.
M25 is a great target for summer observing and astrophotography. It does not have the dramatic glow of a nebula or the spiral shape of a galaxy, but it offers a beautiful look at a young family of stars shining together against the dense star fields of Sagittarius.
Capture Details
| Telescope | Canon 200 mm lens |
| Reducer/Flattener | None |
| Filter | Clip in Light pollution filter |
| Camera | Canon EOS Rebel T6 DSLR |
| Mount | Skywatcher Star Adventurer Mini |
| Total Captured | 197 |
| Total Time | 32 minutes |
| Capture Software | N.I.N.A. |
Guiding | None |
| Processed in | PixInsight |
Backyard Capture Notes
Messier 25 is a forgiving and enjoyable backyard target, especially for wide-field imaging. Since it is a bright open cluster, it does not require extremely long exposure times, but careful focus is important to keep the stars sharp and colorful. In fact was having trouble with my mount tracking on this night and these are only 10 second images stacked. The challenge is preserving the natural star colors while keeping the crowded Sagittarius background from looking too busy. A wider field can help show M25 in context, surrounded by the rich star clouds of the Milky Way.