M13 - The Great Globular Cluster of Hercules

Object info: The globular clusters surrounding the Milky Way are very ancient with M13 being estimated at around 14 billion years old and containing close to 1 million densely packed stars. It is approximately 145 light years distant. At the heart of the constellation of Hercules it lies along the western edge of the Keystone and is just visible to the naked eye from a very dark site. It is the largest globular cluster in the northern hemisphere providing a spectacular view through a modest sized telescope.

Date: 1st June 2007.

Scope: Nexstar GPS 8" at native focal lenght.

Camera: SXV H9F guided by SXV AO and guidehead.

Filters: Scopeteknix manual filter wheel. Astronomik CLS and type II RGB filters.

Lum 15x60 secs unbinned RGB each 15x30 secs binned 2x2.

Captured and stacked in Maxim. Transferred to CS2 using FITS liberator. Combined and processed in CS2.

This was my first time out with the SXV AO unit. I was working at 2000mm focal length and battled to find a suitable guide star that the AO was happy with. Also realised that AO needs a good polar alignment at this f/l if it isn't to spend all it's time bumping the mount. The guiding was a very hit and miss affair. Lessons have now been learnt!