M13 unguided image at 3810mm FL

Shot this image of M13 with the 12" Mak-Cass last night under somewhat hazy skies. These are unguided images taken on the 3600 mount. Total LRGB times are 6.7 minutes (400 seconds) for L and for each color. Focal length is 3810mm, 0.49 arc sec per pixel, STL11K.

I was testing the tracking accuracy (unguided and no PEM) of the 3600 mount, which has a newly developed production worm gear with very low periodic error, below 2 arc seconds for a 5.7 minute worm cycle. Stars on this image measure as small as 1.67 arc sec FWHM. The gears were produced by the machining department under Robert Watters.

This is not a deep image, as most images of M13 go. It is meant to show the core at high resolution without burning it completely out. The skies were not the best - somewhat hazy and not steady. Nevertheless, the ol' Mak still brought out some good resolution.

Rolando

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Here is the whole frame.

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Wow Roland - that is a pretty impressive result!

Am I understanding correctly that you are producing the worm gears (and the worm wheels) in your shop? Is that a fairly new development, I thought you were working with a supplier for the drives in the past (although I'm not sure way I believed that)? As a guy involved in the production of extremely high accuracy gearing (but a larger size) I appreciate how large the challenge is - very cool!

Roland Christen said:These are unguided images taken on the 3600 mount. Total LRGB times are 6.7 minutes (400 seconds) for L and for each color. Focal length is 3810mm, 0.49 arc sec per pixel, STL11K.

I was testing the tracking accuracy (unguided and no PEM) of the 3600 mount...

This is impressive!

Anthony.