M10 in the constellation of Ophiuchus has the honor of being one of the globular clusters in the Messier catalog that is nearest to Earth, lying only 14,600 light-years away. It is a Shapley-Sawyer class VII cluster, which means it has a densely populated but readily resolvable core that gives globular clusters the classic snowball of stars appearance.
Image Data:
Telescope/Mount: Celestron Compustar C14 with Starizona LF reducer/corrector (f/7.5).
Camera: SBIG STL 1100M with Baader Planetarium L,R,G,B filters.
Adaptive Optics: SBIG AO-L at 8 Hz.
Location: Pommier Observatory, Portland, OR, USA.
Dates: 2017-06-27 through 2017-06-28.
Exposures: L:R:G:B=110:60:60:50 = 4 hours, 40 minutes total exposure.
See additional astrophotographs at www.rodpommier.com