Last night was the first clear night in over a month and being a Friday was an added bonus as I didn’t have to get up the next morning for work, so I took the opportunity to align my new Auto Guiding setup. I changed from a side by side mounting for the imaging and guiding telescopes to a piggy back configuration and I needed to align the guide scope to the imaging scope’s optical axis so they are at least pointing in the same direction.
Once that was done I started to image NGC 281 the Pacman Nebula which is a bright emission nebula in the constellation of Cassiopeia. I started imaging at around 9.30 pm and the capture sequence should have taken till just gone 1 am. However once the first image was captured it became obvious that I had a collimation problem with the imaging scope, the reflecting mirrors in the scope were out of alignment causing the stars on the left side of the image to be slightly oblong while the stars on the right are round.
After an hour of adjustments with an Allen key I almost had it sorted out. It still needs some more adjustment to be bang on; collimating a Ritchey Chretien telescope can be time consuming and as it was nearly 11.30 pm I left it at that and did some more imaging.
I generally capture at least 25 – 30 images for stacking in Deepsky Stacker and each image had 6 minutes exposure so I needed at least 3 hours of imaging time. I had no problems with the Auto Guiding at least the PHD Guiding program was doing its job well.
I use Backyard EOS for the image capture sequence so its pretty much an automated process, however I have no automated roof closure system or cloud sensor technology so I have to stay awake as there’s no point in imaging a cloudy sky. Fortunately PHD Guiding alerts you if it loses the guide star and that only happens if a cloud rolls across it. at 1.20 am PHD started sounding an alarm and sure enough the sky had clouded over. I had managed to capture 16 images of NGC 281, not enough for processing but as they are digital images they can be saved and added to at a later time, so time to shut it all down and close the observatory roof and go to bed.
