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Observation by Chris Dole: Jupiter. August 28th.

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Chris Dole


Chris Dole


2021 Aug 28 - 23:27


2021 Aug 29 - 15:55



  • 250mm Dall Kirkham @f16.
  • ASI290mm Camera.
  • ZWO ADC.
  • Baader 685nm IR Pass Filter.

2 ms.


Newbury. G.B.

Target name



Jupiter. August 28th.

About this image

Have had a few clear nights over the last week or so but have been plagued by terrible seeing conditions. So much so that even focusing was generally mainly guess work. This occasion was a little better so an infrared image shows some details at least. The shadow is that of Io. The moon itself is the bright spot just to the right of the shadow. 

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Paul Leyland
Paul Leyland, 2021 Aug 30 - 09:35 UTC

Focusing was mainly guess work on  my scope until I made a Bahtinov mask and started using Bahtinov Grabber software. It works well even at times of poor seeing

For telescopes up to 30cm or so Bahtinov masks are easily purchased though they are not necessarily cheap. I made one out of cardboard for my scope. I never expected to rule a diffraction grating with a craft knife!

The software is available from and it is a Windows executable. As my only Windows box is the telescope controller I never needed to find out whether it runs under WINE on, say, an EKOS-controlled telescope.

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