Location of Photo:
Pommier Observatory, Portland, OR, USA
Date/Time of photo:
2020-08-14 through 2020-08-23
Telescope/Mount: Celestron Compustar C14 with Starizona LF reducer/corrector (f/7.5). Camera: SBIG STL 11000M with Baader Planetarium L,R,G, and B filters. Adaptive Optics: SBIG AO-L @ 8Hz.
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 175,000 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.