Tag Archives: Horse Head

Cold Night; Started B33

It was clear last night, the first truly clear night in a long time, but very cold.  Ambient temperature was -18c. I opened the dome and started things up, to have a series of mount problems.  Guiding was very ragged, jumping around a lot.

I suspect this was Periodic Error Correction being unhelpful – that the PE curve has changed since I adjusted and rebalanced the mount, and PEC was now working against me.  I used an hour to gather new PEC data but never did get to the point where I was happy with the correction.  However, the uncorrected PE was reporting as fairly small (+/- 3), so I decided to just do some guided capture without the PEC.  Turns out that worked very well.

B33-Sum-Red-2x2-11x300This is the time of year that B33 (Horse Head) is visible over the house, between the trees, so I started that for the season.  Unfortunately the previous problems meant that I only had an hour left and, sure enough, after 55 minutes image capture started to fail as the target began to encounter tree branches.

So, just as a sketch, this is the start.  This is 55 minutes of Red light, as 11 5-minute subs.  Guided but no PEC – I’m quite pleased with the guiding.  More light and other colours as the season progresses – it’s forecast cloudy again for several nights now.