Messier 2 is a globular cluster lying 55,000 light-years from Earth in the constellation Aquarius. It is a remarkable globular for several reasons. First, it is one of the largest known globulars with a diameter of 150 light-years. Second, it is a Shapley-Sawyer Class II globular, which means it has an extremely dense and bright core. How dense? Photometric measurements indicate that a 1'x1' area at its core contributes 37% of its light output. At 5' from the core, an equivalent area contributes only 0.02%. Lastly, it has interesting dark lanes arching and branching across its southwest quadrant (bottom edge in this image) that are not present in the other three quadrants. These dark lanes can be glimpsed visually through amateur telescopes.

Exposures: L:R:G:B=75:55:30:35 minutes=2 hours, 15 minutes total exposure at f/7.5.

This image was published in the August, 2024 issue of Astronomy magazine.