Tonight I wanted to get the PHD2 guiding working when doing a meridian flip without the need to calibrate. A month ago we still failed to get this done, however a little experimenting tonight and changing a single setting has corrected the problem. The setting was the ‘Reverse Dec Outputted After Meridian Flip’ one within the Guiding table of the Advanced Setup, for which I ticked and this fixed the issue.
Reverse DEC output after meridian flip needed ticking!
I then decided to try 2 objects either side of the meridian and that worked manually slewing to each and then guiding. What did not work was the slewing automatically to the object in terms of centring on the screen. It slewed to the star, I could see it on the screen, the first object Almach worked ok, but the second object, Deneb appeared on the screen but failed to centre with the error ‘ Failed to auto centre, aborting sequence’ followed by ‘ failed to centre on object with an error less than 50 pixels’. Plate solving works fine, well at least it comes back with success.
Error message failing to centre
So I tried different sets of co-ordinates from TSX including the Topocentric and 2000.0 sets. Neither made a difference, with 2000.0 data used I still got this set of errors which shows an error in pixels of more than 50 in DEC.
DEC Error when centring
So I decided it might be the very bright object I had picked, star in this case, that was causing the problem. So to further my experimentation this evening I choose two different and less bright objects, M36 and M39, once again on different sides of the Meridian. Success !!
60s uncalibrated guided M39 exposure
So after fixing this I am now happy to go off to bed early (9:30 work tomorrow) with a job well done.
GingerGeek and I tried to sort a few things last night, namely PHD2 guiding on both sides of the mount without any recalibration, automated meridian flip within SGPro, focusing and plate solving. After nearly 2 hours we had not fixed any of these problems. So we need further research/reading to resolve.
Instead @9pm I decided to take some more images of M76 since it was due to be fairly clear all night. What I found was this was quite simple to now setup and get working as long as I did not mind performing a manual flip at 11:30pm.
There was one other issue last night which was around the dome closing, it suddenly did this around 10pm, not sure why, I think (I now in the light of day cannot be sure) the relay went off. Looking at the Keogram and then the ASC movie for last night it does coincide with a set of cloud going over so maybe that is why it closed. It will be nice to then get it to reopen when clear, another thing to fix at some point.
So as I say, setting up for the run was straightforward and I used TSX rather than SGPro to centre and platesolve M76 as normal. I then took a sample image of 60 seconds found that the focus was more or less spot on for OIII, despite earlier challenges with focus not working and all was ready to go.
On the point of focus problems, we could not get an accurate V-Curve earlier in the evening, SGPro kept coming up with different focus points after each run and eventually we put this down to the dome and scope not having had time to cool given it only being 30 minutes or so. The outside temperature was around 3℃ whilst the inside was just shy of 9℃. Later in the evening the difference was much smaller (I should remember to record this). I can get the ambient temp for the outside the next day from the FITS header but I have no record of the inside ambient temp, something else to fix.
So I went off to bed just after the meridian flip around 11:30pm and after watching a few frames come down. This morning I took flats and darks and closed the dome which was still open with the first frost of the season having set in and frost was covering the inside of the dome.
After several reboots by GingerGeek who is looking after the observatory I am now logged in. I currently have the dome open and the 12″ centred on Deneb that can be clearly see whilst the Sun is still above the horizon and thus not dark yet.
The rebooting is due to hanging of the NUC. We have had various problems, the external ASI120MC with ASICAP/SharpCap and Firecap seem to cause an issue, we have a problem rebooting and the NUC just powering off and today trying to login through Windows and it was just hung. So lots of niggles.
Tonight I hope to test a single Ha guided exposure on the Elephant Trunk nebula in Cepheus to the North East as it rises and will look to image from 11pm for a few frames before closing the dome for the night. I have already noticed that Deneb is drifting in my FoV so something is still amiss with the polar alignment event though I thought I had it cracked. I will make a note to go back and check it. Currently Deneb is +42 Alt and 66 deg in Azimuth. I think the key will be looking at where I pick the star for polar alignment and making sure I have truly tightened.
So now it is nearly 10pm the sky is getting darker. The strangest thing happened, the dome closed. I only noticed as the image was blank. I checked and the Hitec Weather Station had tripped and closed the Dome. I toggled the Relay and then I could open the dome. Interestingly if you try to open the dome from TheSkyX it tries then stops and resets to closed. For the moment given the clear skies and forecast I have disconnected the Hitec Weather Station software but will reconnect later. Something else to debug.
HiTech Weather Station Software
It’s now 22:21 and dark enough to focus, I spent some time getting the auto focus routine working in SGPro. Interestingly I had to set the step size to 1000 given the 100k steps my FLI focuser is capable of. I also increased the data points to 10 and this gave me enough movement and data to get a good V curve.
I managed to get down to an HFR of on average 6 tonight at focus point 71290. It took me 3 runs to get the right figures. I then made the changes under the 12″ profile within Profile Manager and saved them for future use.
Auto Focus Run
Next I moved on to PHD2 and guiding. Once I got an image I then found I only had hot pixels and no stars. I also had a funny cone of light and something large out of focus and the edge of the tube. I then remembered GingerGeek had fitted a new guard ring to the guider camera and inadvertently moved the position due to a loose screw elsewhere on the fitting. Thus I need to go and focus that the next night out as because I am not there tonight I cannot do this. This also means I am stuck for testing a guided exposure.
Very out of focus Autoguider
So instead I tried a few different exposures with the Ha filter unguided even though I knew I had the problem with polar alignment. I took exposures at 120 seconds and 180 seconds by which time I had trailing, given as I said I had polar aligned and could image for 10 minute exposures in a different part of the sky I need to redo the aspect. Note I did not perform a second autofocus on the Ha filter. I will at some point calibrate the offsets of the filters once I have the auto guider working.
120s Ha Elephant Trunk area still not dark
So at least a useful night to try and get a few things working, a few things to add to the ToDo list but all in all a good evening.
