M71 is a globular cluster in the constellation Sagitta. It a very unusual globular cluster in that it lies very close to the plane of the Milky Way galaxy, as indicated by the innumerable stars in the field. In contrast, most other globular clusters are visible away from the Milky Way because the Milky Way obscures our view of such distant objects. Because it is visible within a densely packed region of the Milky Way, for a long time M71 was thought to be a tightly packed open star cluster within the Milky Way. Recent research shows it is a globular cluster well outside the galaxy, but it is still one of the closest Messier globular clusters at a distance of only 13,050 light-years.
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: 2017-08-06 through 2019-08-19.
Exposures: L:R:G:B=290:30:30:30 = 6 hours, 20 minutes total exposure.
See additional astrophotographs at www.rodpommier.com